By 1967 he beat everyone in front of him including three members of the International Boxing Hall Of Fame.
The 1967 Muhammad Ali who left Cleveland Williams as a skid mark on the canvas beats most any heavyweight. He had movement, speed, power. And he was just approaching his peak - at age 25. I guess it depends on what your defnition of "school" is. But how would someone "school" that guy at the end of that year? IMO, Bowe and Lewis couldn't "school" Holyfield. Holyfield couldn't "school" Michael Dokes or a 42-year-old Larry Holmes. Usyk couldn't even "school" Chisora. Joyce? I love Joe Joyce. But Joe Joyce couldn't "school" Carlos Takam. No. NOBODY "schools" 1967 Ali. Could some all-timer edge him? Sure. Why not. "School?" No.
The question might be asked. who actually tried to beat him at that time? The list is not all that long or all that impressive. Casuals put far too much importance on Ali beating up a shell of Williams, who was already the perfect foil for a young Ali's style.
Also true. Ali might've looked as perfect as any boxer in history when he beat Cleveland Williams but he also beat the worst version of Williams as well.
1966 Ali vs 2018 Usyk Ali: 24 years old, started boxing age 12, 88 confirmed amateur bouts with a record of 80-8 (3 rounders, 247 rounds max), 25 pro (144 rounds contested), stopped 9 pro opponents who were 197+ lbs Usyk: 31 years old, started boxing age 15, 350 amateur bouts with a record of 335-15 (3-4 rounders, 1076-1332 rounds max), 6 WSB (25 rounds contested), 14 pro (105 rounds contested), stopped 11 WSB/pro opponents who were 197+ lbs (pre-rehydration) Ali had been knocked down from head shots twice in the previous 15 fights/4.5 years (Sonny Banks, Henry Cooper), was almost exclusively a head hunter, hadn’t fought a southpaw in 6 years, had lost to at least two southpaws in the amateurs (Kent Green by KO, Amos Johnson by SD), 2013 Usyk was heavier than 28/33 of Ali’s pre-Mathis opponents (Ali himself was very big for his era) and as much as 9 lbs heavier than 1966 Ali, who had gone the distance with 5 of his 25 pro opponents (17-9-1 186 lbs Hunsaker, 15-11-1 225 lbs Sabedong, 18-7 189 lbs Johnson, 23-3-1 188 lbs Jones, 34-11-2 216 lbs Chuvalo), whereas Usyk (the best southpaw heavyweight ever) hasn’t been stopped or dropped with a headshot in a combined total of 376 fights, amateur and pro. 1966 Ali had a highly competitive fight with 49-2-3 European champion southpaw Mildenberger over 11.5 rounds (Ali admitted that he found Mildenberger’s stance and boxing ability very difficult to deal with), who was billed as being 6’1.5 with a 73 inch reach and 195 lbs (4-3-1 in non-KD rounds according to two of the three judges, 154-144 punches landed out of 612-538 thrown according to Compubox; by contrast Usyk outlanded the 6’2, 79.5 inch reach, 198 lbs, undefeated Olympian Hunter 321-190, throwing 905-794 over 12 rounds). Mildenberger had been KO’d twice (once in the 1st round by 30-12-2, 201 lbs Dick Richardson, who had 2 stoppage wins in his previous 9 fights and 0 in his only 2 fights after) and dropped numerous times in 54 pro fights, registered a 31% KO ratio with 0 KO’s in his previous 5 fights and had a 52-12 amateur record, with winning the German LHW championship being his best amateur accomplishment. Usyk has studied Ali extensively, sparred and beaten many opponents influenced by him and has modern advantages in terms of training and "nutrition", as well as a tougher upbringing being from a working-class family in post-Soviet Ukraine, with a modern Eastern European style that Ali never experienced (the old Soviet school was limited to the amateurs in those days). Ali’s objective chance = sub-5%.
It is just about plausible, that there was some cutie in another era, who simply had his number. Of course we have no idea whether such a man existed, or who he was if he did exist.
Whoa.....if we're talking about the Muhammad Ali of 1967 only Lennox Lewis and Larry Holmes would have a slender chance of beating the GOAT. The other guys you mentioned ? No way !