Horde movement broken, way too slow and can't properly move into bubble

[Coolthulhu]

Hordes will set interest properly, but then pretty much ignore it.
Their movement seems incredibly slow, as if only some hordes were capable of movement at all (not related to interest).
Hordes that should enter bubble either disappear or are somehow prevented from spawning. No messages on debug screen.

Log file is filled with

GROUP_ZOMBIE: invalid population here: -1.11665e-016

Though the above log spam seems to be safe, as it looks like it should happen at edges of a diffuse monster group and have no ill effects (it is later clamped to 0).

[RenechCDDA]

Sometime in the last 7 years these have been resolved. Likely due to hordes being completely overhauled between then and now.