and that (unless I missed a post) he thinks D&D ought to work in the "catastrophist" way.
I still have zero idea where you are getting this from. "Ought"? Nope. It shouldn't work this way. It does because there is like, ZERO advice suggesting that it shouldn't. But, I'll get back to that in a second.
/snip
OD&D and AD&D, that's clearly not true. Because you couldn't really "invest" in that stuff, you pretty much were fixed in terms of what you could do, and the spells available had utility across all kinds of situation. 3E, it's definitely possible to argue that it's true, so that's absolutely right for you. 4E it's absolutely not true, because even if you "optimize for stealth/social/utility", you're still a total badass in combat. 5E I would argue that the actual effectiveness difference is likely to be extremely small, and all the spellcasters will be relatively flexible, but you're agreeing with that.
So 5E isn't the odd one on out. 4E is even most like that than 5E. OD&D and AD&D you just can't really do that.
3.XE is the odd one out. Because that's the only edition where what you say is true.
Bree Yark was introduced into D&D, what, forty years ago? Look at the modules of the era. You will see, time and again, language similar to, "If the PC's are seen, the monsters attack, while one at the back raises the alarm". This is hardly unusual.
Heck, I just took a look at Ghosts of Saltmarsh - The Final Enemy. Now, here is the stated goal of the module:
Ghosts of Saltmarsh Page 111 said:
the town council of Saltmarsh once again needs heroes- those accomplished enough to infiltrate the REDACTED stronghold and return with knowledge that will bring about the downfall of the final enemy.
So, right up front we have an infiltration scenario. The advice continues:
GoS Page 112 said:
COMBAT NOT REQUIRED
The characters are considered an elite team that can bring back the needed information. They will likely need to fight some of the REDACTED, but must remain quiet as often as possible to avoid becoming overwhelmed. If they can achieve the mission goals without combat, they're playing smart and well. The intent is to get the players to think tactically and avoid unnecessary fights against a superior foe. Reward the characters' efforts to move past areas filled with REDACTED undetected, but do not hesitate to have the REDACTED react if the characters behave carelessly.
So, what should happen if the PC's are detected? Well, the module does offer some advice:
The primary (and presumed) entrance is the above water gates. ((Note, there are other entrances, we'l talk about those later)). Here's the relevant advice.
GoS Page 116 said:
As long as the characters approach the doors quietly, they do not alert the guards beyond. Tampering with the doors will alert the guards, who demand (in REDACTED) to know who is trying to enter.
The guards can be tricked into opening the doors, but since REDACTED intelligence is high. this will not be an easy task. A character who can communicate with the REDACTED, and who makes a successful DC 18 Charisma (Deception or Persuasion) check. convinces the guards to open the doors for the party.
Note, absolutely no advice on how to adjudicate a failure. However, if the PC's do open the door, then:
GoS Page 116 said:
Once the characters are inside, read the following:
You see a bare, spartan room. Ahead, a short corridor off the room ends in a closed bronze gate. To your left, a sin- gle stone bench runs along the east wall. To your right on the opposite wall hangs a large metal gong; a short metal bar leans against the wall below it.
Several REDACTED glare at you as they move to attack.
Guess what, the entire main level gets alerted by that big metal gong and, really, there is zero chance of you stopping it unless you can somehow kill 9 REDACTED in a single round before any of them can raise the alarm.
But, wait, there are other entrances for enterprising PC's. Now, one of them is the main gates, so, that's a non-starter right off the bat. But the other one is more inviting. It's an abandoned tunnel. Great. First encounter is 3 REDACTED who immediately attack if they become aware of the PC's - no chance of talking to them or bluffing them or bribing them. And 90 feet away through a double door are 45 REDACTED. Granted, there's no chance of the mass hearing due to an ongoing arena fight they are watching, but, that's a move and a double move away for our 3 immediately attacking guards.
So, all in all the odds of success of infiltration are very low. Now, the writers of the adventure knew that, so, they have spaced out encounters far enough that it's entirely plausible that the party will simply murder their way in, do what they're supposed to do, and then murder their way out.
But, again, a single mistake by the party, which is frankly inevitable, results in the entire place being alerted. Fail that Persuasion check above? What is supposed to happen? There's no advice, but, REDACTED are quite intelligent, and very much on a war footing, so, it's not implausible that they would raise an alarm or open the door to look outside while someone is ready to raise the alarm. Go in through the underwater entrances? You're not wounded at this point, so the frenzy sidebar forcing REDACTED to attack won't apply and it will become very apparent very quickly that the PC'S are dangerous. REDACTED are militant, organized and on a war footing, getting ready to attack Saltmarsh. It's not like they're "lazy bullies" of guards (note, how offensive is that stereotype? Sorry, but as someone who has served in uniform and stood guard duty more than a few times, being told that all guards are lazy or bullies is unbelievably disrespectful - talk about something that should be apologized for).