I think it lends an interesting look at a potential direction for the mod - that zombie-concentrated areas can simply never be entirely cleared. Maybe it would be more interesting if it was flat-out impossible(or maybe just very improbable) to hold a city the way we can now. Maybe instead, towns are only worth entering as smash-and-grabs; get what you need, get out, make sure you have a plan the entire way. Most of the upset about the zombie numbers lies in how people are used to hunkering down until the zombies stop coming, rather than trying to make an opening to escape. I just think it is worth a look to see how these spawns change player behaviors before flying off the handle and saying the game needs to be tweaked one way or another.