Well, my reasoning is that Ameko is heavily outnumbered, so she is in actual danger, and if the RP turns into fully-fledged PvP before all the PCs even know each other's names, I can say from experience that it isn't going to last very long.
Also, cheating implies that I'm breaking rules, but Eirina does have the ability to dissolve the conflict. I don't want to use her much until the other PCs are capable of matching her, but unless someone else comes up with a solution for this, I'm not seeing a great number of other options (especially since at least Percy and Lakisha are heading in the direction of full blood-rage).