i don't see why the powder gangers, raiders and sometimes tribals cant attack towns. say, about once or twice a day, a town would get raided.you could kill NPC, getting loot. in the world of fallout, i don't see why people wouldn't try to take over towns. a player could get a reward for killing there, something like 10-100 caps depending on there level, the town's wealth and military presence. say, for example the new California republic was bein attacked by powder gangs, if you kill them, and repel the attack you'd get paid. if they took over the town, you'd not get paid. you would use equipment that you've got from the wasteland or have crafted.
sorry for bad spelling and grammar. i hope you understood my point