Ut says there is a 15% chance of them spawning in forest terrain. So if I go between square 0,1 and 0,0 100 times the odds are I'll get 15 bandits/creatures squads? Also if I bought a bunch of MSPs, equipped them to some NPCs, wore one myself, and sent the NPCs off across terrain would my vision grow?
The spawn chance is only recalculated on cross terrain. If you're moving within the terrain itself, the creatures are already there or they aren't; your perception range only reveals what's already present.