If anything Fedor is closer to Mike Tyson (without the level of fame on controversy)
But from a purely fight record point of view I see more of a comparison to Tyson than Ali. Don't misunderstand, Tyson and Fedor are polar opposites in terms of personality and conduct.
Both at there prime cleaned up their respective divisions, Tyson unified the heavyweight division and developed an awesome reputation as "the baddest man on the planet" while in truth never having to beat any GREAT fighters (certainly none who transcend their era and go down in boxings hall of fame)
You could say Fedor's time in Pride was similar, beat all comers in his organisation and ruled for a long time without having to fight many true legends (Nog and Cro cop aside)
I think both came with a massive amount of hype, and whilst both were amazing fighters and legends in their respective sports neither really had the number of fights against the quality of opponents to fully justify their reputations and perceived greatness.
Tyson never beat the likes of Lewis, Holyfield (although he lost to both when they did finally meet up) Riddock Bowe, Kilitchco etc. I mean he had this ora of greatness without ever really beating a great fighter.
Razor Ruddock? Hmm well look what Lewis did to him, Tyson's achievements were great and like Fedor you can only beat what is put infront of you but the bottom line is he never beat the other hall of fame fighters of his era (as Fedor never tested himself outside of Pride's talent pool)
Post Pride Fedor also reminds me of post jail Tyson, each trading of reputation Tyson beating the likes of Frank Bruno and Bruce Seldon but able to headline massive bills because he was IRON MIKE TYSON regardless of he he fought and Fedor went from Affliction to Strikeforce etc and heading the billing regardless of whether he was fighting a washed up Tim Silvia or a never was BRett Rogers...he was Fedor baddest man on the planet it didn't matter who he fought his hype from previous achievements were enough to sell events.
And finally Fedors recent back to back defeats remind me of when Tyson finally ran into Holyfield and Lewis, the years of inactivity and lack of testing yourself against the best crept up on him and he was exposed.
I just hope Fedor has enough sense to not continue the Tyson trend and end up embarrassing himself and his legacy in the style Iron Mike did with loses to such no hopers as Danny Williams and Kevin McBride.
Iron Mike and Fedor, to of the biggest names ever in their respective sports. Both exciting and supremely talented, both hall of fame no brainers but neither is on a level with the GReat Muhammed Ali as neither beat the very best and took on every test they could (tyson never beat Lewis, Holyfield, Bowe and Fedor never came to UFC to prove his status)