Only way that there will be "less" KOS, is more zombies, spawn them everywhere around the map like in open fields near the airfield, in treelines, ect... and make multiple zombietypes, some are stronger some are faster, ect... Because if zombies could like 3 hit you, I don't think you would keep standing still to shoot someone when there are 3 zombies chasing you that can knock u down instantly... So you will have to clear the zombies first, before u could make a shot, so its not really less KOS but atleast it'll take more time for the bandits to take a shot at some times...