FrozenNorth
Hero
I think Chaosmancer’s point is that you are applying a double standard: unorthodox builds are scrutinized for any inconsistencies between fluff and mechanics whereas any inconsistencies that already exist in the PHB are handwaved as “not important”.No game is perfect. Having to jump through these hoops to "prove" your point just ends up supporting mine. The game will have moments that don't make sense. That doesn't mean that it's a good thing to amplify and increase the numbers of those moments.
I think a better example of Chaosmancer’s point is Thieves’ Cant. There are completely standard Rogue builds that have no reason to know thieves’ cant (Scout Rogues for instance). I doubt you would argue that Scout Rogues are homebrew because of this inconsistency.
Yet you are treating Barbarian Knight as homebrew because of an equivalent inconsistency.