Helmets, Robots, and Shoggoths. Problem solved.
Seriously though. If the system is broken to favor headshots, you could attempt to make a rules adjustment to fix it. Perhaps increase the to-hit penalty for heads, which I feel is usually a bit small in most games. From the front, the human head occupies an area about 1/5th the size of the torso, and 1/10th the size of the whole body. Hitting a target that size consistently should be
hard. To make it more "fair", any shot that falls in the range between old penalty and new penalty could be a body shot. (Missed the head, hit the body).