I think the arbitrary point control is the problem. I can't see why people can benefit from the same locations. Multiple teams of Urchins stealing from the same area and if there are two many on the same site, the bobby (Police) investigating and scaring them off (lost to the players for a few turns but slowly come back) creating a risk reward mechanic, even using this to deny resources in this way.
Come to think of it, where are the Police? You'd think that the Police would be present in a game about thieves? Patrolling every turn and detecting in an area.