It isn't always about rankings. And how good a guy was. I think we have a different meaning of legend.
The fact that Chuck Liddell basically saved MMA in the U.S. He was easily...easily the most popular fighter in North America. That has a lot to do with his legendary status.
It isn't all about the top guys being legends. People are legendary for different things. Not just being a top fighter.
Chuck was not the most popular fighter in north american, mma yes but fighter no.