Have your character break their own internal logic, and you’ve sunk the story along with it.
Yes ♥︎
But troupe play…? Your one character can do things that are bad for your other character? My dorks have gotten so brazen with troupe play that they jump in and start portraying all kinds of NPCs, secure in the knowledge that I’d step in if the NPC really did have a hidden, un-self-evident agenda, like if the NPC is secretly questing for a specific ring and just biding their time to grab it or w/e.