The answer in this question states that a zombie in the zone may die of despair for every two zombies killed in the zone, but it doesn't state whether or not if this happens before or after triggering additional zombie spawns due to their presence. So if I have two zones next to each other like so: [12][0], and I clear the zombies down to: [4][0], is there a chance the zone with 0 zombies in it will spawn one zombie before the 4 in the zone that originally contained 12 zombies die of despair?
Also along the same line of thought: If I have a single zone of 12 zombies, and I kill 8 of them, leaving 4, will the zone generate additional zombies first and then kill off 4 from despair, leaving the zone potentially with some zombies left, or will the 4 die first and then the zone will no longer spawn any zombies?