Or make an Arena 'entrance' in a bunch of these towns, but make them all link to the same Arena map. And when you leave, you're back at the town you entered in. I can see more people using it that way.
Any action or inaction in a position of power will always grant you enemies
It dont needs to fit with the fallout story, but it fits with fallout world. (a training and competitive area is needed in a fallout world)