The more conflict avoidant the agents in an area, the more there is to gain from being an agent that seeks conflict.

This is only true if the conflict avoidance is innate and is not instead a form of reciprocal altruism.

Reciprocal altruism is an ESS where pure altruism is not because you cannot take advantage of it in this way; if you become belligerent, then everyone else turns on you and you lose. Thus, it is never to your advantage to become belligerent.