They idea is that they represent, say a salty crew of pirates, a group of followers, etc. They are the red shirts. As they level up they get become more competant until they become the howling commandos.
Even if mind controlled, since they only have one action per round, it has limited effect. The real problem I've seen is that they are easy to injure as they have a large surface area to engage in melee.
The PC that hired the Mob NPC wants to let them go as they are only usable in the wolderness due to the amount of room they take up. I might reduce the total area.