This is an out of character problem that should be addressed by talking to your players at session 0 ...The manner in which you create characters is irrelevant here because it's an interpersonal issue, not a mechanical or narrative one.

It is actually both, considering that it is entirely about how problematic players design their characters to be problematic. In a roleplay game, the narrative is an interpersonal narrative, which means interpersonal issues are linked to narrative issues.

Which is exactly why I made the Session 0 plan that I did. Don't need to rely on good faith when you pre-bake it into the character creation. It has worked flawlessly for getting rid of problem players.

Because I've seen it work many times with very ordinary players. Ordinary, but participating in good faith, which is the bare minimum. If you don't have good faith, you shouldn't be playing.

Unfortunately, it fails more often than it works, because everyone thinks they are in good faith from their perspective, even the edgy loner wolf player. Because everyone goes into a game with different expectations. Which is why I built my session 0 to avoid the problem altogether by setting strict expectations of players and their characters.

I am participating in good faith. You're just not understandstanding me. Don't be a dick and police my tone just because you fail to understand my perspective. That's arguing in bad faith.