How are people handling initiative in situations where the only combatants are Player Characters? Specifically when you have two (or more) actors all on the same space on the initiative track where the standard "heros first" tie-breaker wouldn't apply.

My initial thought would be to use some sort of competetive check between the players (likely a 'second' initive check), but I'd be curious to know how others have handled this situation in their games.

If tie ->Higher Agility goes first. If tie on agility -> the one who rolled more boons goes first.

Personally, I'd do boons as first tie-breaker, and compare Agility (or Fellowship in a social encounter) only if boons were also tied.

I also imagine that the Party Tension Meter would be moving a lot, unless the competition was essentially playful. Depending on the nature of the PC vs PC struggle, I might not let them use the talent slots or power on the Party card either. If they're both wooing the same NPC, or it's an argument or actual fight between the PCs then every action would move the Tension Meter, and they wouldn't get to use their team powers. If instead it was something like a chess match or a foot race between the PCs, I'd probably only move the tension meter as a 2-bane or chaos star result… but such light-hearted situations are also rarely worth rolling initiative over in the first place.

EDIT: I just remembered that there's a precedent in the rules for Competetive checks where the person in Reckless stance wins ties. Page 52 to 53 of the Player's Guide. I'm not sure it's relevant to an Initiative check, but it's arguably the closest thing to official word on the subject.