There should be a permission that prevents people from claiming several regions. Ideally, the group setting would determine how many regions a user can claim.
Also, it should be able to prevent users from un-claiming a region by permission settings.

Otherwise there is a risk that a user, in search for clay, claims one region after the other to harvest the clay, leaves it behind stripped of the resource and moves on.
If I can tell the user that they can claim one (or according to the user group several) regions, and prevent them from claiming others additionally or un-claiming the current region, this would not be a problem.