I'm not an expert on MMA but is Anderson Silva not the most versatile fighter, maybe ever? I've only watched UFC for over a year or so but I've never seen somebody utilize all the tools - kicking, punching, kneeing, elbowing - nearly as effectively as him.
Henderson is slightly stronger than Silva, a better wrestler, and harder puncher and he gave Silva more of a run than all of Silva's previous UFC opponents, yet it wasn't enough.
It seems to me Silva has the perfect combination of skills: he's long and lean so he has incredible reach, deceptively strong, exceptionally quick and accurate, and is unpredictable (most fighters compared to him almost seem one-dimensional in their skills), very slinky so he can weasel out of tight grips, and just a very smart fighter. I think he could beat rampage even though they're in a different weight class. Silva uses his knees and legs all the time and he makes contact regularily. One knee to the face or leg to the face/body is the equivalent of 2 or more hard direct punches.
Among other things, he knocks a guy out using an upper-cut elbow in this vid. I've never seen that before:
https://youtube.com/watch?v=I_107aDVxPk