So we've got a 4096 x 4096 map, only the hostile creatures spawn heavily in the NW corner, less so as you proceed east and south. It's evidently filling in from the NW corner every time it spawns, and by the time it gets to the SE corner, there's maybe one hostile creature every 100 squares or more in any direction. If that! Is there any control for this, or something in the database?
Note: I necroposted it in an earlier thread of mine; if you see it, please answer here so the tags will be more appropriate.