Bowe and Lewis if both are in their best possible shape. Possibly Holyfield, but his biggest problem would be his willingness to go in the trenches when he doesn't need to. If he did that with Frazier prime vs prime, Frazier wins.
Aside from Bowe, no one can pull it off. Even Holyfield, who is greater than Bowe, can pull it off cuz of styles. Holyfield would give him a tough time. Add Mercer and McCall too-maybe. I favor Joe over both, but if they can nail Joe right, and lay a huge barrage on him, they might crush Joe. But I favor Joe over Mercer 3-1, and over McCall 4-1, though he would have to settle for decisions over both. Joe and Bert Cooper would make for a damn good fight.
The division went in a bad direction for him. A lot of giants who throw big punches. Probably his best advantage is his spirit, endurance, and that his style will be unfamiliar to the modern guys. Still the list could be 10 or more names long. On their best night: Foreman, Lewis, Bowe, Vitaly, probably Holyfield, etc. Versus the very best Mike Tyson you can find it's slightly Tyson favored and would probably be traumatic to watch regardless of winner. Neither would be the same after.
I don’t know about who would beat him, but I know the fight I’d look forward to most would be FOTC Frazier vs 92/93 Holyfield
I don't give 90s Tyson much of a chance against prime Frazier (it would be very different if it was the 80s Tyson). Joe might get knocked down, but he'd get back up. Joe also wouldn't be intimidated by Mike, which earns big points. I see Mike getting stopped in 9. I think the 90s Foreman would definitely catch Joe and knock him down, but get hit way too much to gain much ground. Frazier by 12 round UD. Prime Holy would be the fight of the 90s. He'd do real good with his darting style, but it's inevitable he'd get knocked down and Frazier would be all over him. Joe by TKO in 11. I don't see the 90s Lewis getting away with too much, though his jab would work good, and undoubtedly his right uppercut would rock Joe mightily several points in the bout. I don't see LL getting sloppy against Joe as he did against Rahman and McCall (Frazier being a class way above either of those guys imo). But I do see him getting hurt bad and nearly stopped. SD for Frazier, whether Lewis is with Steward or not. I see the Bowe who beat Holy the first time flooring Joe several times within a hard fought fight (it would be nowhere near the wipe out the first Foreman fight was). Joe rocks the bejesus out of Bowe a couple of times, but Bowe stays up and eventually Joe succumbs to the right uppercut and bludgeoning infighting of Bowe. Bowe by stoppage in 9. Keep in mind, I consider Joe a way higher ATG than Bowe, and any other version/era of Bowe would get whupped imo. Golota would do well against Joe, but he would either foul out or quit by the 8th round.
Possibly 1991 Mike Tyson. He still had fast, accurate hands and ATG punching power and would land early and often vs Frazier while being the bigger man muscle and weight wise.
He may very well be able to do it. A much bigger and stronger man with good world class handspeed and a hard SHW puncher and good fundamentals. That combined with 6 inches in height and 40 or so pounds in solid muscle mass. I wouldn't count him out TBH.