Lewis was actually one of the least humble fighters to even win a major titlle. MVC is a cringeworthy fanboy.
The Klitachko brothers wouldn't be able to hang with the likes of Bowe, Holyfield, Holmes, or Tyson. The Klitschko brothers are just a few steps above John Ruiz.
Lewis is very arrogant and bitter, not even a close comparison to Wlad. Wlad also has become quite arrogant in his reign of success, but he doesn't drudge up the past and bad mouth others publicly the way Lewis does.
If by humble you mean frequently repeated lines such as "I'm like a fine wine, I get better with age" and 3rd person references like "It takes more than a left hook and a haircut to beat Lennox Lewis", I guess you could say that. :smoke