For real? You honestly don't think that he could be a factor in UFC or Pride's LHW division?
Personaly the only LHW that I believe could give him a hard time right now would be Liddell, Sobral and Vera, if he fights at LHW in the UFC.
In Pride I would say his toughest fights would come from Silva, Rua and Nogueira. Arona would be tough as well.
I can think of alot of guys that he would almost definitely destroy in both organizations.