D&D 5E Low Level Wizards Really Do Suck in 5E

[Celtavian]

As far as I can tell, it's more that there are a bunch of awful spells to avoid (Witch Bolt), a new mechanic that needs to be planned around (Concentration), some fairly high variance based on DM rulings and use of grids, and finally the eternal dnd question of how often your group rests.

They can be just fine. They can also suck. I've seen both

These problems are as it has always been. I keep hearing that 3E wizards has a better starting selection of spells. That wasn't the case at all. As far as the PHB goes, there were only a handful of useful spells that nearly every wizard took to be effective. As more books came out maybe that list increased, but as far as I know spell such as grease and color spray were the go to spells of every mage that wanted to be highly effective at low level. Cantrips were a joke for damage meaning a first level mage generally had three or four spells per day for use. Maybe 4E was different, but the low level 5E mage has more options than the low level 3E mage by a good measure due to the effectiveness of cantrips.

 

[Celtavian]

Grappling does not impose the restrained condition on either party. It just reduces the grappled party's movement to zero. That's it. No advantage to attack unless you also push them prone.

Yep. Read that later. I was thinking of pinned.

Still puts the action economy and damage race in our favor, which I would have welcome. It heavily restricts movement, especially in the tight quarters we were in. To maintain it further removes attacks from the opponent, especially the pack leaders using glaives.

It would have been a bad idea all the way around. Each failure would have been more costly. I've seen grappling attempted in melee range, it's rarely a good idea.

 

[Celtavian]

Karinsdad,

Just to make your diagram more accurate, the flaming sphere was located where you placed the b. Anyone that stood in that area took extra damage as the sphere did it's normal save at the end of your turn and he rammed it into anyone using the bonus action attack. The goal was to be able to move the sphere to seal and not give them the corner to shoot around with cover. Sphere in wrong location on your diagram. We wanted to keep the advantageous corner clear forcing them to the outside giving us a clear path without cover to attack them if needed, such as with thunderwave.

PC 1 and 2 were five feet back. Remember the hallway is 20 feet long. We gave them 15 feet to work with. We were interested in limiting visibility as stated earlier and preventing a single push from knocking us out of our position. We weren't overly concerned with grappling because we were confident we would win any contests. Monk's acrobatics +7, warlock +6 athletics. We use 4d6 method for rolling. Warlock/fighter has a nice set of stats. Only real way to play one. Monk's wisdom and dex are both good. And as I stated, grappling works out in our favor eliminating attacks by them as well as each failure further slanting damage in our favor. Given the glaive wielding pack leaders do 1d10+3 with reach capable of attacking from behind the Fang and another gnoll, they figured their four against our two was a win for them. Fortunately for us, Heavy Armor Mastery heavily slants the numbers in our favor.

After the Fang and his two sons were dead, the regular gnolls were bags of hit points and little more than a nuisance no matter what they did. If they grappled, they lose their attack. It's a half move to stand up if they knock us prone. They can maybe bring six at most against one character. We still had healing, sleep, sphere damage, thunderwave, and another aid. We were good.

Seems to me you're not very accustomed to patient parties using good tactics. For example, it is unlikely we would have attuned the rapier in the dungeon. Too risky.

 

[FormerlyHemlock]

FWIW, I agree with what I gather KD is arguing: that shoving and grappling could have been an effective strategy. (I haven't looked at the map details though.) With the bonuses described (+7ish acrobatics), the gnolls have maybe a 35% chance of grappling successfully, on par with a melee attack. However, pushing the monk or warlock prone roughly doubles the damage of everyone who goes after you, so unless you're the last one it makes sense to do. Similarly, grappling lets you bring more gnolls into play both for attacks and damage absorption, possibly as many as nine depending on terrain, although from what Celtavian has said it sounds more likely to be five on the grappled guy and five more on the front line. (Flaming Sphere damages both sides so is kind of a wash.) In short, it would be advantageous.

Now, does that mean the gnolls would actually do this? They don't know the party's stats, so it's more a question of "how do gnolls normally fight?" Does the pack leader solo enemies to show how tough he is? Does he drag enemies back to his buddies as a "look, I'm bringing you food!" kind of deal so the pack can tear into them? Does he suit back and laugh while the pack exhausts itself wearing down enemies (killing off his rivals) before entering battle himself at the very end? The MM is silent on these questions, but it seems to me that Celtavian's DM chose #1. That's fine, but it looks to me like #2 would have been harder for the PCs to deal with. Celtavian's arguments for why grappling would have been a bad idea ring hollow once the grappled vs. pinned confusion is corrected.

 

[KarinsDad]

Karinsdad,

Just to make your diagram more accurate, the flaming sphere was located where you placed the b. Anyone that stood in that area took extra damage as the sphere did it's normal save at the end of your turn and he rammed it into anyone using the bonus action attack. The goal was to be able to move the sphere to seal and not give them the corner to shoot around with cover. Sphere in wrong location on your diagram. We wanted to keep the advantageous corner clear forcing them to the outside giving us a clear path without cover to attack them if needed, such as with thunderwave.

PC 1 and 2 were five feet back. Remember the hallway is 20 feet long. We gave them 15 feet to work with. We were interested in limiting visibility as stated earlier and preventing a single push from knocking us out of our position. We weren't overly concerned with grappling because we were confident we would win any contests. Monk's acrobatics +7, warlock +6 athletics. We use 4d6 method for rolling. Warlock/fighter has a nice set of stats. Only real way to play one. Monk's wisdom and dex are both good. And as I stated, grappling works out in our favor eliminating attacks by them as well as each failure further slanting damage in our favor. Given the glaive wielding pack leaders do 1d10+3 with reach capable of attacking from behind the Fang and another gnoll, they figured their four against our two was a win for them. Fortunately for us, Heavy Armor Mastery heavily slants the numbers in our favor.

After the Fang and his two sons were dead, the regular gnolls were bags of hit points and little more than a nuisance no matter what they did. If they grappled, they lose their attack. It's a half move to stand up if they knock us prone. They can maybe bring six at most against one character. We still had healing, sleep, sphere damage, thunderwave, and another aid. We were good.

What part of "this was just an example of ways to break through a choke point" did you not understand and had nothing to do with your specific encounter? No matter how much you claim that these are terrible tactics that you would welcome at your table, it does not make it true.


With regard to your specific encounter, I find that the very act of sending the most powerful monsters at your team to be a mistake on the part of the Fang (i.e. the DM decided poorly). The Fang should have sent in mooks to find out what tactics you were using.

Monk's acrobatics +7, warlock +6 athletics

These are good stats. The odds of pulling a PC are low. But, not impossible. In fact, with two foes trying to do this at 34% and 30%, the odds of at least one of them managing it are 53.8%. If both monsters on a single round tried to pull a PC out of position, their odds of managing it better than the odds of it not occurring. Worse if two mooks are trying it (48.375%), but still good odds.

But, if a DM is not going to have the monsters use tactics to break a choke point and just have them be meat bags of hit points for the PCs to whale on, of course the players can manage to multiple their results.


Course, all of this goes back to what brought up this conversation. You stated that Cure Wounds is a lot more effective than Healing Word for your group, you then made the claim to crush higher level foes who outnumber you almost 5 to 1 as a pretty standard encounter that only needed a single cure wounds spell, you then admitted that your PCs have excess hit points (which makes them tougher), you then admitted that their stats are higher than normal (which makes them tougher), that the DM knew about your meat grinder tactics, but sent the toughest foes to get mangled first, that there was no other way around for them to surround you, that the DM allowed you to set the place of the encounter, that the DM did not use shove or grapple to break the choke point, and in fact you insist that a DM doing so is a terrible tactic.

Well yeah, it's terrible for the PCs, but compared to be hacked and burned to death, it's a pretty darn good one for the NPCS. The NPCs are already getting slaughtered. If I understand your setup:

 _________
|   c e g
| S__d_f___
|ab|
|12|

could easily result in the following in a single round.

 _________
|   l no
| SX_m_p___
|kb|
|j2|
|i |
|h | ____
| g        |
|  f       |
|   e      |
| d        |
|c         |

X is the square where both the grappled PC 1 and grappling NPC a is (grapple allows one to carry the target, so he can be in the same square). Sure, there are two OAs in this situation and NPC a takes flaming sphere damage at the end of his turn, but he was taking flaming sphere damage at the end of his turn anyway.

Now how much of this occurs is up to initiative order after NPC a grapples PC 1 around the sphere, the actions of the PCs and NPCs during those turns, where PCs and NPCs are at the moment, the exact location of walls and such, etc. But, breaking through this line seems pretty darn easy and as was illustrated above, the odds of doing so were 53.8% if it were the fang and/or the pack lords doing it (or any other foes with 16 Str).

Sorry, but your opinion on how wonderful your group tactics are suspect if you absolutely refuse to see that there are ways around them. To me, it just seems like your DM isn't trying too hard to mess up your group tactics.

Seems to me you're not very accustomed to patient parties using good tactics. For example, it is unlikely we would have attuned the rapier in the dungeon. Too risky.

Too risky? For adventurers?

A group of adventurers are trapped in a crypt with limited food and their Identify spell states that it is a +1 rapier and it's too risky to attune to that +1 rapier in such dire circumstances?

Dude, you are a riot. The stuff you write.

Does your group attune to the +1 rapier in a city where one of your PCs can go on a rampage using it to attack town folk left and right? Your "attune out of the dungeon" POV with a Sword of Vengeance could easily result in a fight between the King's guards and the PCs, just because of a minor situation where that PC took some damage. Personally, if I'm going to unleash a cursed weapon into the world, I want to do it when I am trapped in a crypt anyway.


Our group sometimes use good tactics. They sometimes use bad tactics. Unlike the claims of some people here, my group has people who sometimes do awesome things and sometimes make mistakes. My players do not manage to take out 23 higher level foes because their DM doesn't set up such easy encounters to shoot fish in a barrel.

 

[Celtavian]

FWIW, I agree with what I gather KD is arguing: that shoving and grappling could have been an effective strategy. (I haven't looked at the map details though.) With the bonuses described (+7ish acrobatics), the gnolls have maybe a 35% chance of grappling successfully, on par with a melee attack. However, pushing the monk or warlock prone roughly doubles the damage of everyone who goes after you, so unless you're the last one it makes sense to do. Similarly, grappling lets you bring more gnolls into play both for attacks and damage absorption, possibly as many as nine depending on terrain, although from what Celtavian has said it sounds more likely to be five on the grappled guy and five more on the front line. (Flaming Sphere damages both sides so is kind of a wash.) In short, it would be advantageous.

Now, does that mean the gnolls would actually do this? They don't know the party's stats, so it's more a question of "how do gnolls normally fight?" Does the pack leader solo enemies to show how tough he is? Does he drag enemies back to his buddies as a "look, I'm bringing you food!" kind of deal so the pack can tear into them? Does he suit back and laugh while the pack exhausts itself wearing down enemies (killing off his rivals) before entering battle himself at the very end? The MM is silent on these questions, but it seems to me that Celtavian's DM chose #1. That's fine, but it looks to me like #2 would have been harder for the PCs to deal with. Celtavian's arguments for why grappling would have been a bad idea ring hollow once the grappled vs. pinned confusion is corrected.

I worked out using grappled in the conditions of the battle. It would have worked out to an easier encounter for us. What happened when they tried to grapple:

1. Movement ended with the gnoll leader and his sons up front. If they attempt to grapple immediately, they cannot move the target that round. The gnoll pack leaders would have had to drop their glaives to attempt to grapple eliminating any damage by them.

2. The conga line does not work. As I stated earlier, it is half move to move through a creatures space. That would have reduced their move to 15 feet per round and requiring them to coordinate in an exact fashion to clear a spot. This took more than one round to accomplish and was impossible to accomplish without getting burned by the flaming sphere for the people that ended their 15 foot move near the sphere.

3. If they did only half move, where the flaming sphere was set up would have burned three to five of them a round even moving in and out at half move.

4. By the time the gnoll leaders did grapple if they did so on the first try, the gnoll fang was still deadd releasing the grapple having done less damage.

6. The location of the sphere did not allow gnolls to stand without getting burned even waiting to move.

7. Any gnoll attempting to grapple had to shoulder its spear or shield. Each missed grapple attempt by a gnoll did less damage once again.

I redid the encounter using grappling tactics. Gnoll fang was still dead on round two. Gnolls did flood in the room at a later time having done less damage because a grapple attempt does nothing. It was real bad when they missed the grapple. Attacks became spread between five characters rather than one allowing wizard and Eldritch Knight to use their area of effect spells easier on the gnolls. thunderwave hammered them. The characters in the halls were still able to withstand attack with only 5 attacking them if they spread along the hallway hitting for less damage the warlock can easily take. The cleric has an AC of 18 as well and a 16 Con. She was able to withstand a few hits and maintain concentration.

The grappling tactic sped up the battle, allowed more AoE use, put action economy in our favor, and spread the damage over more targets. We were still able to use the sphere to maintain control and redirect gnolls as we wished and do damage to them.

Ran this battle three times with the grappling tactics. All three times we won and it resulted in an easier fight. The focused damage of the Fang and the gnoll packer leaders against the warlock/fighter ran three times resulted in a near win one time for them. Lucky crits on the warlock with a glaive are nasty.

If you don't use the rule that they have half move moving through another creature's square, the results are better with grappling and a conga line attempt. That isn't the rule. Half move through another creature's square. Moving back and forth is a bad idea for a large group of creatures.

It was interesting to see how the grapple and shove tactics worked. It removed damage while setting up other creatures for better attacks. Given the warlock/fighter has DR, the increased chance to hit for prone had a minimal effect given the creatures still weren't going to all get an attack on him. I think it is unreasonable for anyone to expect 23 gnolls to go after one guy when others attacking are present.

I remember trying grapple tactics in 3E against enemies. It never worked out in the enemies favor. Always wasted time and damage trying to do something that if it failed even once, greatly improved the opponents chance of victory. It isn't much different in 5E. The best outcome was when the grapple hit the first time, but it still resulted ultimately in a loss. Oh boy, when the grapple attempt missed or a couple of miss, extremely bad for the gnolls. I also had to decide how many would try to grapple and how committed they were to the attempt while getting burned. It was an interesting look at gnoll psychology.

Suffice it to say next time we are going to allow the mob through and ready AoE attacks to use on them. That is a better strategy than standing in the hallway allowing them to focus fire two characters. It was night and day when two thunderwave spells in 15 foot cubes washed over the gnolls at the same time. Much faster way to kill them. I think we'll used staggered spacing to direct them into the room while setting the casters in position to hammer them upon entrance.

 

[Celtavian]

What part of "this was just an example of ways to break through a choke point" did you not understand and had nothing to do with your specific encounter? No matter how much you claim that these are terrible tactics that you would welcome at your table, it does not make it true.


With regard to your specific encounter, I find that the very act of sending the most powerful monsters at your team to be a mistake on the part of the Fang (i.e. the DM decided poorly). The Fang should have sent in mooks to find out what tactics you were using.



These are good stats. The odds of pulling a PC are low. But, not impossible. In fact, with two foes trying to do this at 34% and 30%, the odds of at least one of them managing it are 53.8%. If both monsters on a single round tried to pull a PC out of position, their odds of managing it better than the odds of it not occurring. Worse if two mooks are trying it (48.375%), but still good odds.

But, if a DM is not going to have the monsters use tactics to break a choke point and just have them be meat bags of hit points for the PCs to whale on, of course the players can manage to multiple their results.


Course, all of this goes back to what brought up this conversation. You stated that Cure Wounds is a lot more effective than Healing Word for your group, you then made the claim to crush higher level foes who outnumber you almost 5 to 1 as a pretty standard encounter that only needed a single cure wounds spell, you then admitted that your PCs have excess hit points (which makes them tougher), you then admitted that their stats are higher than normal (which makes them tougher), that the DM knew about your meat grinder tactics, but sent the toughest foes to get mangled first, that there was no other way around for them to surround you, that the DM allowed you to set the place of the encounter, that the DM did not use shove or grapple to break the choke point, and in fact you insist that a DM doing so is a terrible tactic.

Well yeah, it's terrible for the PCs, but compared to be hacked and burned to death, it's a pretty darn good one for the NPCS. The NPCs are already getting slaughtered. If I understand your setup:

 _________
|   c e g
| S__d_f___
|ab|
|12|

could easily result in the following in a single round.

 _________
|   l no
| SX_m_p___
|kb|
|j2|
|i |
|h | ____
| g        |
|  f       |
|   e      |
| d        |
|c         |

X is the square where both the grappled PC 1 and grappling NPC a is (grapple allows one to carry the target, so he can be in the same square). Sure, there are two OAs in this situation and NPC a takes flaming sphere damage at the end of his turn, but he was taking flaming sphere damage at the end of his turn anyway.

Now how much of this occurs is up to initiative order after NPC a grapples PC 1 around the sphere, the actions of the PCs and NPCs during those turns, where PCs and NPCs are at the moment, the exact location of walls and such, etc. But, breaking through this line seems pretty darn easy and as was illustrated above, the odds of doing so were 53.8% if it were the fang and/or the pack lords doing it (or any other foes with 16 Str).

Sorry, but your opinion on how wonderful your group tactics are suspect if you absolutely refuse to see that there are ways around them. To me, it just seems like your DM isn't trying too hard to mess up your group tactics.




Too risky? For adventurers?

A group of adventurers are trapped in a crypt with limited food and their Identify spell states that it is a +1 rapier and it's too risky to attune to that +1 rapier in such dire circumstances?

Dude, you are a riot. The stuff you write.

Does your group attune to the +1 rapier in a city where one of your PCs can go on a rampage using it to attack town folk left and right? Your "attune out of the dungeon" POV with a Sword of Vengeance could easily result in a fight between the King's guards and the PCs, just because of a minor situation where that PC took some damage. Personally, if I'm going to unleash a cursed weapon into the world, I want to do it when I am trapped in a crypt anyway.


Our group sometimes use good tactics. They sometimes use bad tactics. Unlike the claims of some people here, my group has people who sometimes do awesome things and sometimes make mistakes. My players do not manage to take out 23 higher level foes because their DM doesn't set up such easy encounters to shoot fish in a barrel.

That's what it did result in with the back line getting burned.

The DM chose to play the gnolls afraid of getting burned after their initial archer foray caused quite a few to get burned. They backed up waiting for their gnoll leader to kill them. Didn't seem out of character for a gnoll. We had the sons and the single gnoll shifting back and forth to avoid the burning in the ten foot space.

At this point the fight is over. I reran it using your tactics. The gnolls did break into the room. As I stated, the only real threat were the pack lords and the Fang. The regular gnolls had little chance of defeating the warlock/fighter with armor mastery.

Unless you truly believe that a pack of gnolls would run into a room of five people and all twenty three attack the warlock/fighter backing in and out on him ignoring everyone else, we still win. The cleric is no slouch in the AC and hit point department. The wizard I believe had 16 AC. The fighter had 16 as well. With +3 and +4 to hit for the gnolls, the spread attacks worked out in our favor.

I will give you this. The grappling tactic did allow the gnolls to enter the room. After going over the fight again, it almost seems like we should have done in that in the first place. The wizard and Eldritch Knight were able to coordinate thunderwave hits that hammered the gnolls in mass allowing the warlock to feast as most of the gnolls were in one hit kill range after that. The Flaming sphere wasn't stuck in one place. The wizard was able to use it to do damage and place it where the gnolls couldn't mass against any single character without giving us AOOs if they wanted to avoid getting burned. Our attacks do more than the average damage of the sphere, that also helped. Placing our backs against the wall and standing side by side also avoided the gnolls massing against us.

I'll remember this next time. We'll coordinate allowing a certain number of creatures through to take full advantage of AoE spells. Thank you for helping to improve our strategy. Letting a mob of creatures through and letting them engage is much better than letting them focus on two characters in a hallway. This discussion did turn out to be fruitful.

If you're ever in the same situation, better to let the mob enter the room and have readied AoE spells. Let that be the lesson.

 

[Celtavian]

One last addition to the strategy if grapple/shove is used to allow a group of mobs to break into the room according to class:

1. Cleric should play defense. The cleric should use the Dodge action. Their priority is keeping the bless active. If multiple mobs attack the cleric, cleric should Dodge. Even if they shove her prone for a round of attacks, Dodge cancels Advantage from Prone. With an AC 18, you still have very little chance of being hit even by four gnolls. The gnolls chasing you act as a form of crowd control. You should cast spiritual weapon instead and attack with spiritual weapon while using the Dodge action. You should focus on damaging the mobs on the warlock/fighter to bring them in range of a hit kill to keep the warlock/fighter getting temporary hit points.

2. Wizard after unleashing thunderwave should also play defense. He should use his action for Dodge. He should use his bonus action to move the flaming sphere once again focusing on the warlock/fighter to keep hit points on mobs low for temporary hit point cycling.

3. Eldritch Knight should switch to sword and shield boosting AC and doing melee damage. If necessary also switch to Dodge to keep gnolls occupied. An Eldrithc Knight should be able to do a good job fighting gnolls and go back to back or side to side with warlock/fighter.

4. Monk same as Eldritch Knight. You should close ranks as much as possible. If they wish to continue grappling, each gnoll that grapples lowers the group damage. Each failure further lowers the group damage as well as takes a weapon out of their hand. Use thunderwave or shield as needed.

5. Warlock/fighter. Do what you do. Fight to the death. Cycle those temporary hit points.

Don't get flustered. Stay focused. Win the combat. A group of gnolls is not a tough fight. They're bags of hit points that eventually die. Now a group of hobgoblins or bugbears that large require you run. Orcs can be pretty nasty too because of Greataxe damage. But gnolls not so much.

 

[KarinsDad]

The regular gnolls had little chance of defeating the warlock/fighter with armor mastery.

Unless you truly believe that a pack of gnolls would run into a room of five people and all twenty three attack the warlock/fighter backing in and out on him ignoring everyone else, we still win. The cleric is no slouch in the AC and hit point department. The wizard I believe had 16 AC. The fighter had 16 as well. With +3 and +4 to hit for the gnolls, the spread attacks worked out in our favor.

I will give you this. The grappling tactic did allow the gnolls to enter the room. After going over the fight again, it almost seems like we should have done in that in the first place. The wizard and Eldritch Knight were able to coordinate thunderwave hits that hammered the gnolls in mass. The Flaming sphere wasn't stuck in one place. The wizard was able to use it to do damage and place it where the gnolls couldn't mass against any single character without giving us AOOs if they wanted to avoid getting burned. Our attacks do more than the average damage of the sphere, that also helped. Placing our backs against the wall and standing side by side also avoided the gnolls massing against us.

I'll remember this next time. We'll coordinate allowing a certain number of creatures through to take full advantage of AoE spells. Thank you for helping to improve our strategy. Letting a mob of creatures through and letting them engage is much better than letting them focus on two characters in a hallway.

Glad I could help.


In my experience, there are a lot of things DMs can do to really mess up the PC's day. The same tactics that the PCs can use, the NPCs can use. It's just that the DM typically has to figure out good NPC tactics and synergies ahead of time. It rarely, at least IME, works out so well on the fly at the table. The DM actually has a lot more tactics and synergies he can use because he has total monster selection every single encounter, but in order to take advantage of that, he usually has to figure them out ahead of time.

Why? Because the players have dozens of gaming sessions to fine tune their tactics and hone what works and what does not work (as per your new coordination of AoEs tactic by letting multiple foes through a choke point here) with characters that they are constantly trying to improve. The DM tends to have new sets of NPCs/monsters with a lot fewer options each that are not optimized and the DM has never seen them work together before.

If I had a dollar for every combat over the decades where I thought as a DM afterwards "I should have done xyz instead, that would have really challenged the PCs", I'd have a lot of dollars.


In your example, something as simple as the gnolls coming from two directions (for example, the pack lords and half of the gnolls coming to your choke point, the fang and the other half of the gnolls coming down a secret escape tunnel or some such) would have probably forced your PCs to flee. As capable as your PCs and players are, the only reason you can take on these mega-CR encounters is because the DM allows you to control the battlefield. Take that away from your players and you'd be generally limited to standard level CR encounters. Maybe a little higher due to your group rolling for stats, extra hit points at first through third level, and your player's ability to optimize and strategize, but in fights where you do not control the situation, I think you would see the advantage of Healing Word over Cure Wounds a significant portion of the time in combat (which is what started this side discussion).

 

[Celtavian]

Glad I could help.

I don't care for getting called out about tactics. So the "getting smoked" comment set me off a bit. I also don't like dismissing tactics out of hand. That's why I kept coming back. I like to consider how to beat something. That's a major part of the fun of the game.

In my experience, there are a lot of things DMs can do to really mess up the PC's day. The same tactics that the PCs can use, the NPCs can use. It's just that the DM typically has to figure out good NPC tactics and synergies ahead of time. It rarely, at least IME, works out so well on the fly at the table. The DM actually has a lot more tactics and synergies he can use because he has total monster selection every single encounter, but in order to take advantage of that, he usually has to figure them out ahead of time.

True. Our most difficult battles are when the DM takes the time to construct a powerful strategy by the NPCs.

Why? Because the players have dozens of gaming sessions to fine tune their tactics and hone what works and what does not work (as per your new coordination of AoEs tactic by letting multiple foes through a choke point here) with characters that they are constantly trying to improve. The DM tends to have new sets of NPCs/monsters with a lot fewer options each that are not optimized and the DM has never seen them work together before.

True.

If I had a dollar for every combat over the decades where I thought as a DM afterwards "I should have done xyz instead, that would have really challenged the PCs", I'd have a lot of dollars.

I don't worry too much. Players forget stuff too and kick themselves. In general, I try to play the creature as true to its nature as I can. If I do that, I feel good at the end of the day.

In your example, something as simple as the gnolls coming from two directions (for example, the pack lords and half of the gnolls coming to your choke point, the fang and the other half of the gnolls coming down a secret escape tunnel or some such) would have probably forced your PCs to flee. As capable as your PCs and players are, the only reason you can take on these mega-CR encounters is because the DM allows you to control the battlefield. Take that away from your players and you'd be generally limited to standard level CR encounters. Maybe a little higher due to your group rolling for stats, extra hit points at first through third level, and your player's ability to optimize and strategize, but in fights where you do not control the situation, I think you would see the advantage of Healing Word over Cure Wounds a significant portion of the time in combat (which is what started this side discussion).

Would have been a nightmare. We specifically checked for a passage allowing them to pinch us. We set up by the entrance just in case we had to run. At the time we didn't know what gnolls could do exactly. We were worried. Fortunately, gnolls are one of those creatures that looks worse than they are. Low hit rolls. A marginally useful special ability. Low AC. Good hit points. I noticed there are a few monsters like this in the MM that go both ways. For example, did you look at the Chasme Demon? Holy mother of...The thing does 64 points of damage a hit with no save. Can you imagine a group of chasme attacking a party? It would make a group of vrocks or higher level demons look like chid's play. Yet they are CR 6. How many 6th level PCs can take a 64 point hit?

Then you have the Demilich. Not sure what they missed on this creature. A level 17 wizard with power word kill gets to the Demilich and kills it. Only way the Demilich lives is to encase the wizard in an antimagic field and keep it on him until everyone else goes or get lucky with the howl ability. If the wizard gets to go, the demilich dies immediately.

Even with the gnoll encounter, if that had been kobolds or hobgoblins half as many would have been too much. The kobolds would have died easier, but all those attacks with advantage even with missile weapons would have done some damage. Hobgoblins are nasty in groups.

It's an odd game. I don't feel like the gnoll encounter was really a CR 8 given their special abilities aren't as good as other special abilities. Even orcs are somewhat scarier because you can't outrun them and their swingy damage can really hurt you. One orc hit is like a gnoll crit. An orc crit is like a hit from four gnolls. It's bad news.

I don't think we would have attempted the encounter with a fighter or ranger as the main tank. Definitely with a barbarian. Maybe with a paladin. The warlock/fighter is uniquely durable in a fight against a bunch of creatures more so than a fight against a single tough creature. We're surprised at how well the warlock/fighter synergizes. He was even able to do more burst damage against the Fang using Hellish Rebuke, which helped bring it down so quickly. He specced out a warlock13/fighter 7 that will eventually allow him to use eldritch blast for maximum effect while swinging his weapon once as a bonus action. He'll even be able to Action Surge now and again to double Eldritch Blast or another spell and hit with his weapon while maybe using Armor of Agathys or Hellish Rebuke for a ton of damage. It's a surprisingly powerful combination. He even gets to use his Eldritch Knight spell slots to cast warlock spells to add a few extra slots between short rests and use the shield spell. I doubt we win the fight without his Fiend Pact warlock/fighter synergies.

So many factors to take into account for both the DM and the players.