Maybe he could have, maybe not, it's just speculation. He did at least show some potential with With You intro scream and And One bridge. We have no way of telling or prooving. Also yes, Crawling is only a small part, but there are other ones too. Just a few examples: Somewhere I Belong, Numb, One Step Closer, Faint. I still respect him, he sings how he wants, those songs are just examples which sounded better live to me.