Let's face it, a horse is only a temporary mode of transportation. In a situation of groups of zombies, they would be able to surround you. Or they could scare the horses while grabbing at them and the horse would either raise up and throw you off..or while it's kicking the zombies, they all continue to come and surround you and pull you off.
I would think a tank would be better. However, like all vehicles they need fuel and hence you would have problem. At lease the zombies could not get into the tank.
I would think a tank would be better. However, like all vehicles they need fuel and hence you would have problem. At lease the zombies could not get into the tank.