after you edited your post, i will edit mine.
so basically nothing changes? if they get to the hill they can camp straight afterwards? that's a bit pointless since what will happen is, they will go to the hill, camp, and stay there until the next hill comes up, dont get me wrong, i think it will help, but it won't change much
and also, u can close off places which take ages to access for both zombies and humans, so no on can camp there, and open hallways normally have 2 doors, and if there is 1 human there, you can have 2 zombies go round at the same time, or have all the zombies overrun that 1 area, its not a huge deal if they camp in open places, since they are easily accessible.