I find it a challenge to get 2 boys to fight. At least I think they are fighting. They run off in different directions and throw punches. There is no description in the action area of either boy. The girls do not fight, they just giggle and play train. Some times I can get a parent to tickel that is cute.
Somewhere on the forums I once read about a boy who began to do Kung Fu when dropped onto another child (I think it was a sister, but am not sure.) I've tried several times to get that to happen with no success, but I have seen what you're talking about and have to admit it makes me chuckle. :P