Sorry for the minor derail, but I want to vent.
I know "theatre majors" are the favoured target here, but I never had much issue with them. In the group I'm in, by far the worst guy is a self appointed HEMA expert.
Like many players, early in the campaign he was a little salty when the dice didn't go his way. We're now late game. What was a little bit of whining is now lengthy rants about historical inaccuracy, especially when it comes to full plate. "I shouldn't get disadvantage to stealth! Men-at-arms spend years in their armour and would have learned to compensate. How did I take damage from that? I'm in full plate!" etc.
He has never worn armour in real life of course, but he has no shortage of YouTube videos he insists we watch.
It's like that old copy pasta where the weeb complains about katanas not being god tier weapons, but with armour.
And of course, being a fighter that dumped Wisdom and Intelligence, he has strong opinions when it comes to saving against spells.
TL:DR : I'll take a Critical Roll fan over a YouTube history autist.
The Theater Majors I've encountered are just like that sperg only with
feelings instead of spergy youtubes. "It just doesn't fit with a paladin that they'd be disadvantaged on stealth in full plate", "I shouldn't have to roll to seduce because my character's back story", "Enemies shouldn't want to fight me because they know I'm a force for good", "I don't want to actually roll, I just want to say something and have it happen in an interesting manner".
History spergs, I dunno I haven't had an issue with. I tell them they're right, but its a fantasy game and the rules be like that. If they don't stop whining I tell them to Roll Perception... Ok, you are sitting at a table. You look around and find that the door back your car is right over there. In front of you, there's a gamemaster who is sick of this argument for the 10th time, and table full of people playing a game you are ruining because you are arguing the rules instead of playing the game. What do you do?
Cause if we're being fully historically accurate, your character is going to be too tired to move stealthily after about an hour or two, and even uninjured will need a day or two after an extended battle to recover being wrapped in that much weight and insulation. Cause while I do agree D&D's armor rules in any edition past 2nd are bullshit (and 2nd & 1st have their own issues too) with how much they penalize heavy armor for only a few more points of AC, they also don't bring with them some of the worst aspects of full plate, namely the general inability to move much, let alone move 25 feet in 6-10 seconds all day long. Like if we're going for full accuracy, yes you should get some pretty hefty DR, but your speed should about 10 feet and you should need to keep rolling saves against exhaustion.
Anyway, its the horseshoe theory; Like
@Corn Flakes says, neither a theater major and realism sperg want to actually play the game, they are both just spergs who just want to indulge their brand of spergery.
You guy doesn't sound like a history sperg though. He sounds like a munchkin trying to use history to justify his munchkinery when it suits him. Cause with History Spergs my experience has always been listen to their complaints, I generally agree with them, but that's not how the rules work and the rules have been made to resemble reality while providing balance for different characters and builds, not slavishly mirror reality. Either they deal with it having accepted they made their views known, or they leave.