I take it you don't actually know how tough cheerleaders are? I'm assuming too that you are thinking of the dancers that you see at sporting games and not the rather awesome competitive cheerleaders.
Cheerleaders are very used to being kicked, kneed and punched in the face as well as the rest of their bodies, they lose teeth, have black eyes, cracked ribs, cracked vertebra, broken noses and that's just from training which is more than most martial artists can say. Stunting is inherently dangerous. It's not the cheerleaders who need to learn the difference it's the OP and the writer of the article.
My cheerleading daughter by the way has won several full contact fights, she says it's easier than Cheer.