To keep it at strong-faction-free, any member part of the gangs that had owned a northern town before will not be able to start TC there, and won't be able to enter during Necro timer, also being kicked to the World Map if the timer is started.
I didn't mention Guardians just because they represent no real force in my opinion.
Don't be one-track minded. TC rather depopolates an area than bringing life to it.
I would prefer junk town jt with another 3rd Enter zone is the best place for pvp. Large area, plenty of buildings.