I think "without getting touched" is unfair for some fighters, simply because their style won't be quite as defensive as IP Man's. For example, I think Boyka would clear the 10 black belts just as easily if not more than IP Man, but I don't think he'll get through without getting hit.
A better question would be, who'd clear the 10 black belts with as much ease as IP man.
I don't think Boyka would have an easy time of it at all. He was getting tagged quite a bit by just two guys in some shitty underground ring in the last movie.
Boyka isn't even that good in his own universe, he got destroyed by Iceman, who in turn was beaten by Monroe Hutchen.
Iceman who had learned to grapple and kick, is not the same Iceman that Monroe beat. Also, Ip has trouble with a heavy weight boxer, a heavy weight boxer that Boyka would have completely beat up if he was allowed kicks as Ip was during the first round.
Those 2 fighters that Boyka fought were considered veteran, high-end fighters. The 10 black belts that Ip fought, how many fights have they had? Were they even experienced fighters or did they simply earn their black belts through sparring?
Come on. A boxer who learned grappling from some old guy in jail kicked Boyka's ass. And he might have won their first fight, too if he wasn't poisoned.
Were they? The last guy before the Nightmare was considered good, but those two guys were as random as the 10 black belts. And Ip Man was banned from using kicks in the first round iirc.