Why not just disable region take over if density too low? That will force the hand and make it where people can't expand.
...Yeah, that's a good idea. You get a cookie.
I think it probably needs to be slightly more complex than that (perhaps a mechanic to explicitly abandon a region if density is low, so that you can prioritize keeping the ones you actually care about, and potentially even move the realm bit by bit if part of the problem is your location), but yes, I think we should implement that, and soon.
