When you look at it, 90% of grappling whether is be Judo, BJJ, Sambo, or Submission Wrestling is all the same. The difference comes with some minor detail, a few techniques, and the biggest one, EMPHASIS!
In Judo you learn the same armbar you learn in BJJ, the difference is that BJJ spends 90% of the time there where's Judo is more of a 70/30 split with Throws and Submissions.
Can't really say what's superior to what...in MMA, anything can happen so you can't say BJJ > Judo or Sambo > BJJ because there's just no way to prove it(Sambo guys have beaten BJJ guys, BJJ guys have beat Judoka, Judoka have beat SAmbo guys, etc.)
I guess depending on the rules it can be said...
Sambo rules = Sambo > all
Judo rules= Judo > all
BJJ/Submission Wrestling rules = BJJ/Submission Wrestling > all
Streetfight = who knows, one punch ends a fight, 5 guys beating on you makes grappling essentially useless, 1 judo throw will **** you up, an armbar will stop a person, weapons change the game, there's too many variables.
But Fedor comes from a strong Judo and Sambo background, which makes it fine for him. He has amazing throws, his technique is top notch, he's got a very good solid submission defense game, and he is damn slick and quick when it comes to slapping on a sub.