The tards tend to be very strong. There was a kid down the street from me and when he freaked out he was very very strong for his size, no idea how strong he would be with training. The other side of that is you might build a killing machine by accident. Think "Of mice and men". If you end up with a guy who can throw 400 Lbs around like nothing and has the mental age of a 6 year old you might have a big problem on your hands.