Holmes went to the body nicely but the only difference was he was consistent. Pretty much all the time he'd put something downstairs, Ali didn't.
Ali went downstairs well against Bugner, and although I've never seen it, I understand that he went downstairs against Blue Lewis pretty well. The key punch of his rematch with Spinks may have been a left hook to Leon's ribs. Muhammad also jabbed frequently to the sternum in that one. No, Ali wasn't consistent to the body, but he was definitely not an individual that the body could simply be exposed to with abandon, because he would take advantage if it was there. He's been wrongly stereotyped by writers who haven't studied him closely enough as someone "who never threw a bodypunch in his life," just as his hook has occasionally been dismissed as "just a slap." (Tell that to Spinks and Bonavena.)
Ali was a fluid fighter with great upperbody movement who slipped punches with movement. The same can't said about Holmes. He may of wanted to be like Ali, but he was not in the same class as Ali by any stretch.