I respectgully disagree. We don't play it that way at my table, but if you do at yours that is ok.
There are boundaries defined by the class certainly, but IMO those boundaries are very broad and using feats gives you ample space to be well outside those stereotypes for all classes other than Warlock. For some classes, like Rogue, you can be anything.
Here's a quote from the PHB's "Classes" section:
Class is the primary definition of what your character can do. It’s more than a profession; it’s your character’s calling. Class shapes the way you think about the world and interact with it and your relationship with other people and powers in the multiverse. A fighter, for example, might view the world in pragmatic terms of strategy and maneuvering, and see herself as just a pawn in a much larger game. A cleric, by contrast, might see himself as a willing servant in a god’s unfolding plan or a conflict brewing among various deities. While the fighter has contacts in a mercenary company or army, the cleric might know a number of priests, paladins, and devotees who share his faith.
*See the emboldened parts that prove my point, and then the examples below it for even more proof that theme/flavor is a part of your class. If you need even more, see the table below that shows the 12 different classes and gives a completely theme/flavor-based "
Description" section of the table.
Your table runs it differently from how the game is written. That's fine. Just don't try to use your table's playstyle/houserule to try and invalidate my argument anymore, please.
The classes are a thing because of the mechanics. Let me put it this way. I could bring my character to the game and play for weeks, RAW, without you knowing if the character was a Warlock or a Wizard. If when you did figure it out it would be because you counted number of times I said "sorcery points" or keyed in on words like "arcane recovery".
I think you got that confused, as Warlocks recharge spells on a short rest and don't have sorcery points. I would know what class you are automatically when you use one of your abilities. Even if you went out of your way to avoid saying them, I could eventually narrow it down based on the spells you cast and how you recharged your spell slots.
Even if you mentioned absolutely no class features or spells, made no mention of your hit dice or anything else mechanical that could give you away, if you played it by the books, I could figure out what class you were at the first time you or anyone else said "Spellbook", "Tome of Shadows", "Imp/Quasit/Sprite/Pseudodragon familiar", "Pact Weapon", "Talisman", or "Otherworldly Patron".
Classes are a thing because of flavor. If there was no flavor or theme, it would just be mechanics and characters would only be chosen based on who was the most mechanically effective. Classes were made not to give a pool of different mechanics, they were made to give mechanics to fulfill a theme/idea that someone had for a class. This isn't some "chicken or the egg" riddle (the answer to that is egg), it's "do people create classes to have different mechanics, or do they create mechanics to fill different classes' thematic niches?", to which the answer is undeniably the latter.
Background, race or feats can do this for any class though, any character can be sneaky. It is easier for a Rogue because parts of it (specifically expertise and for sneaky cunning action) is built in to the class without considering feats but any character class can be not jsut good but outstanding at these things. When you consider the so called "optional rules" every class has mechanics they can use to make them outstanding. Your barbarian can get expertise in slight of hand. He can get expertise in stealth too and if he does those things and rolls or invests in a high dexterity he will be better than the vast majority of Rogues walking around, not better than all of them, but better than most of them.
Dude (and I mean this as a gender-neutral dude, I was raised by a Californian mother), you're comparing Apples (Classes), Oranges (backgrounds), Bananas (feats), Blueberries (skills), and Strawberries (race), and trying to replace all parts of a fruit salad with just one or two fruits.
Like in my example, if the Rogue class said "Rogues are sneaky and good at sleight of hand", but gave them no features that let them take the Stealth or Sleight of Hand skills, and someone was complaining about that, it would not be a valid argument to say "well, just choose X-background/race/feat!". Dude, just no. That's not how it works. The class says that it's sneaky and quick with their hands, so the class should have a mechanic that let's them do that. It would be even more disingenuous to say "well, just wait X-levels to choose X-feat instead of actually improving your rogue features if you want that part of the rogue theme!", hopefully for obvious reasons. If a class's flavor text gives you a theme, the class's mechanics should give you that theme.
And, again, you keep pretending like feats aren't optional, or at least are accepting it in the most grating way possible. I've been in campaigns where feats weren't allowed, I have friends that don't allow feats in their campaigns, and I've even met some players that hate playing with feats (which I absolutely cannot fathom from the standpoint of a PC).
IMO, the mechanics ensure a modicum of balance, but there is no problem with ignoring the intended or stereotypical "theme"
And I never said there was anything inherently wrong with that. I just said that there is a line and that there are circumstances where it can be crossed. I even gave examples on circumstances where I feel that it would be unacceptable to say "just reflavor it".
But why does that matter? You can still use the only feature that really matters to the build (bladesinger extra attack). With GWM your character will do A LOT more damage in melee than a "traditional" bladesinger and the tradeoff will be a slightly lower max AC (at 2nd level 2 points lower in max AC compared to a traditional bladesinger in bladesong and 1 point higher when out of bladesong). Also compared to a "traditional" bladesinger you can dump intelligence and bump constitution to make up for the slight AC difference.
I get that they are abilities you can't use, but they are abilities you don't need with your build either, so why does it matter?
First off, you're highly understating the tradeoff. You're trading bladesong (+10 movement speed, +INT mod to AC, +INT to Concentration saves, and the minor benefit of advantage on Acrobatics), Song of Defense (negating damage with spell slots as a reaction), and Song of Victory (+Int to damage while bladesinging). It matters because you're trading all of that in order to get one feature (two if you count the minor benefit of the light armor proficiency to make it easier to get medium/heavy armor proficiency). That's a huge tradeoff to be able to kind-of replicate your theme, and not even in the way that I want. I don't want to play a bladesinger, if I did, I would play one. I want to play a spell-striking Gish, which the Bladesinger does not do a good job at replicating.
1) We had a Rogue who played in my group several years ago and she found a girdle of giant strangth and a lengendary warpick and she stopped using finesse weapons once that happened. Now that is a bit unfair because it was not part of the original build theme but we had fun and she did more damage then if she had kept using her short sword.
2) The bladesinger is different than this Rogue example though. There is a huge mechanical advantage to sneak attack so there is a big opportunity cost to not using it. There is no equivalent penalty to not using bladesong if you equip armor and use a great weapon.
3) A bladesinger not using bladesong because she is in half-plate is the equivalent of a battlemaster not using his artisans tool proficiency. They have that ability, but it is a ribbon feature on that particular build. Now if that battlemaster was a high-wisdom, high-charisma guy with approriate skills who wanted to use it for whatever it would be a different story.
1) Are you really going to force me to amend my statement to "ooh! Awesome rogue features! I can't wait to use them until the DM gives me two high-level magic items that let me be more effective ignoring my class features than actually use them in tandem with my magic items!!!"? That anecdote, although very strange, doesn't contradict my point. The PC didn't ask to do that, they didn't know that the DM was going to give them those items. I assume that most people that do know that their DM is going to give their specific characters certain magic items upon character creation are going to choose to create characters that would better benefit from using those magic items. If the DM says at character creation "You're going to get a Staff of the Magi at X-level", the player's almost definitely not going to say "Okay! I'll play a Barbarian!!!".
2) There's a huge mechanical advantage to Bladesong (+INT mod to AC and Concentration checks, +10 speed, access to the 10th and 14th level features), too. Maybe Sneak Attack isn't a good comparison, I think Rage is more equivalent. Someone that wants to play a barbarian with a high AC almost definitely won't wear Heavy Armor, because that prevents them from using Rage, Relentless Rage, and a ton of subclass features.
3) You keep using false equivalencies. This one is slightly more accurate than the "blowgun" argument of your previous post, but it's still wildly wrong. Tool proficiencies have no in-combat effects for fighters, but Bladesong has a ton. A more accurate equivalency would be telling a character that wants to play a Juggernaut that they have to be a Barbarian wearing Heavy Armor, even though they can't use Rage and tons of other features. Bladesong is a core feature of the Bladesinger subclass (it's in the name of the subclass, for goodness' sake!), just like Rage is a core feature of the Barbarian class, but the tool proficiency feature of Battlemasters is by no means a core feature of the subclass.
Yeah. You have to build the character you want to play in order to play the character you want to play.
No one told the Hexblade that if you want to play a martial Warlock that we already have the Pact of the Blade, and thus we don't need any more martial warlock options. No one told the Unarmed Fighting Fighting Style that if you want to use unarmed strikes in combat that you have to be a Monk or race with natural weapons. No one told the Swords Bard that it couldn't exist because you could just reflavor the Battlemaster fighter as singing while using team-buffing maneuvers, or for that matter, that the College of Valor subclass already existed, and thus that it couldn't exist. Or the Chronurgy Wizard for Divination Wizards, or Oath of the Watchers Paladins for Horizon Walker Rangers, and so on, and so on. No one said "choose the original option, but use weapons/armor that make you sub-optimal" to any of them, so why should they now? "You have to build the character you want to play in order to play the character you want to play" is being directed very specifically to this class that people in this thread and others are asking for, but not any of the in-game official examples of some overlap that was allowed to exist in 5e. Why should an Arcane Gish be forced to specifically choose backgrounds and races to allow for their character concept to exist when no one told the Oath of the Watchers Paladin that it doesn't get to exist because "it can just get heavy armor with a feat, and is allowed to use melee weapons if they want"?
And it is not a "ton of feats", it is two feats - medium armor proficiency and weapon master and only then if you pick a race that does not have these. And you don't even need that feat with some races.
I did say "heavy armor", didn't I? Just checked. Yes, I did. That's 3 feats. Wizards get 5 ASIs. That's 60% of your ASIs and 12 levels that you have to use to just get the armor/shield/weapon proficiencies that an Arcane Gish class would give you in 1 level. Even if you say "just be a Variant Human/Mountain Dwarf/Githyanki/Custom Lineage!", that's 2 feats (well, still three for a Mountain Dwarf or Githyanki that wants Shields) that you have to use that otherwise could have gone to GWM, Crusher/Slasher/Piercer, Fey-Touched, capping out your INT score, or another feat. Additionally, an Arcane Gish class would give you a Fighting Style at level 2, so in order to replicate that, you'd have to expend another feat (and that wouldn't include the Arcane Warrior fighting style that the class would get, which would be a Wizard version of Divine/Druidic Warrior from TCoE).
Even so, this is completely besides the point. The nitpick in me forced myself to point out your error with counting the amount of feats required. This tangent is now becoming a red herring, because a class would solve all of this with one level and not require any ASIs to be used on the class identity.
Just to be clear - Any character that wants the GWM feat needs to take a feat to get it, so that is no different for a bladesinger. So when you consider that, the bladesinger is exactly 1 feat behind a character of a class that comes with medium armor, if they don't choose a race that gets this for free.
I am aware. However, for a Bladesinger to benefit from all of GWM, they have to expend another feat to get proficiency with at least one heavy weapon. That's two feats behind, or three if they're going for Heavy Armor (like I said), or four behind to get a fighting style.
FEATS ARE NO SUBSTITUTION FOR CLASS FEATURES
(Not yelling, just making my point clear.)
No. If you want to play an arcane gish (and that term itself is debatable), then build they arcane GISH you want to play and don't worry about the abilities you are not using.
Arcane gish is a catchall. I'm not debating that term, as that debate and a discussion of it would be a red herring.
I want a class. I have gone in-depth about how a class could accomplish things that the current subclasses couldn't (all armor, shield, simple/martial weapon, Fighting Style with an Arcane Warrior Fighting Style, different subclasses of the class that use the same base features (spell strike) but in different ways and with different spells, an arcane ward class feature, and so on).
If you want to play an armored GISH mixing magic and melee with his weapons it is.
Why? Why is that a "reasonable stance"? I cannot understand it at all. By the same argument, why aren't Rangers a Druid or Rogue or Fighter subclass? Why aren't Paladins a Cleric or Fighter subclass? Why is it reasonable to let a Primal Gish class exist (Ranger), a Divine Gish class exist (Paladin), but not an Arcane Gish?
Does that not seem contradictory to you? Does it not seem gatekeep-y?
Do you honestly think it would be balanced to have a 6th-level GISH that can let loose a GWM attack with a lightning bolt kicker 3 times a day? That is FAR more powerful than a paladin smite at 6th level. At 11th level you can actually do this up to two times a day with a bladesinger (assuming a day of rest before adventuring), which is about right, and is STILL way ahead of a Paladin smite in terms of damage, both on that turn and throughout the day.
No, because I didn't say that. I said that they should be able to Spell-Strike before level 11, not that they have to be able to use Lightning-Bolt in Spell Strike before 11th level (or if I did say that, I misspoke, and meant that spellstrike should be available before level 11, not the specific "lightning bolt-spell strike" combination).
It would not be OP unless you made it be so. I already have a rough-draft for a Spell-Strike feature that would make the feature not be OP (taking an action (eventually just a bonus action) beforehand to cast the spell, requiring concentration, giving the option of losing the spell if you miss enough, etc). Chromatic Orb is just one d8 higher in damage than a Divine Smite (and it's a more commonly-resisted/immune damage type), so I don't think that allowing a level 2 Arcane Gish use an action beforehand to store Chromatic Orb inside of their weapon to automatically deal its damage on the next turn to any target it hits would be OP.
I'm not going to address the rest of your math, because it's doing math on false assumptions about the feature's mechanics.