I even think somebody like Jersey Joe Walcott on a good night could have taken Foreman in Zaire. Joe Louis was still a very dangerous fighter when they first met in 1947 and Walcott by all accounts beat him soundly--(even by Louis's own admission.) Additionally, Walcott had a style that could negate George's power-and I could see him wearing Foreman down for a late stoppage just as Ali did.
Bit of a left field take, but maybe Sam Peter? He had the punch, dude's chin is legendary, strong as an ox, he's big enough not to get shoved around and i think he's a definite improvement over Lyle, who got George in serious trouble.
Evander Holyfield Oleksandr Usyk Larry Holmes Chris Byrd Tim Witherspoon Prime Not saying they all win but I think the best versions of these fighters could trouble Foreman immensely.
Holyfield and Bowe from their first fight both have the grit, stamina, and chin to get it done against Foreman.
Gotta say I’m shocked by some of the names being thrown out. I guess Ali’s win wasn’t that great after all Honestly, not many. Outside of the prime Ali, there is really only Louis & Liston that I would definitively favour, & then, not by much. The really 50-50 on the fence line call would be a peak Holmes. He had a style advantage, but also didn’t & couldn’t defeat Foreman the way Ali did - grappling, wriggling his way out of shots, or finding angles to minimise the damage. He tended to box safely or fight back if hurt (big mistake here) - &, of course, he beat no one special, which makes judging him cautious stuff. That would be a touch & go affair.
I honestly don't think that Young would've survived the killing barrages that George threw at Ali. He almost crumpled when faced up against a worse version of Foreman- And although I love Jimmy, we do have to fully consider the implications of their infamous match. Witherspoon, Holmes, Usyk, Holyfield (I've talked about him previously against this version of Foreman), and even Peter are all good picks from above.