See your assuming that zero is a slow retard. As you see in one of the animations that i provided above, he has a move that "jets" him in a certain direction. His targeting computer can analize the trajectory in which sonic is coming at him and compute the best evasion course. Your also assuming that sonic is in very close range. FOr zero to not notice him coming from a distance would be improbable. And even if by some miracle sonic gets to him, have you ever tried to punch/jump on hard metal? YOu cant really damage it. Im sure a hedgehog of all animals would do just the same. If zero can take multiple hits from bastards that Sigma had, iim sure a little "peck" by a hedgehog would be nothing.