I remember that, thinking: ‘he might be onto something.’
I have to share a situation i think many have seen similar ones since 2.0:
My group is in a medium sized room (think a little smaller than righteous stand right after the barracks, before going up to the ramparts), one covering the front door in melee with me covering him with ranged and two holding the back door, can’t remember which map. There is one small wall blocking view from both doors, with a litte extension in going to the 2 player defended door.
What happens is 7 gors spawing from behind that little extension because no one was looking there for a couple of seconds. I was seeing it happening as i turned around from the one guy (horde was barely existing anymore) to see how the other two were doing (stupid elves and their 6th sense, i guess).
No hole in the wall, floor or ceiling, no barricade they could have climbed over. They spawned there out of thin air, quickly one after the other. A.I. director stopped what he was doing shortly after me looking there, but too late, i had already seen it.
What now follows is a very bad paint (the red circles could be bases if our characters were tabletop figures, blue is beastmen):
It was mind-boggeling to see it so clearly. The system determined that if no one is looking there, it would be good to go to spawn enemies, even if a player was standing literally 1 meter away from that spawn point and with no clear entrance for enemies.
Skaven use all the various little holes on the map when they ambush, rotbloods are spawing relatively far away in full groups, and beastmen appearently spawn out of thin air where they want.
I think they are somehow tied to that ‘no one is seeing the spawn point’ rather than distance. That may be to make their spawn behaviour to be the middleground between skaven and rotblood horde spawns, but in reality it’s very buggy and not that thought out (as harsh as that may sound). There is no rustling like skaven do when climbing out of their holes, they just heavily breathe down your neck as their horns are already stuck in said neck (we did not loose the run, gladly). There needs to be a limit on horde spawns going more in the rotblood direction, with some distance to the group.
I had time and fiddled around with Paint 3D, look at this even worse version of the above: