Regardless of where they fought, I wouldn't give Chavez Jr much of a chance of making it out of the first round
People can't see through their emotions. McClellan was a popular fighter with his KO power while Chavez jr. is among the most hated, but in reality they fought at similar level. Chavez seems to have a sturdy chin so I believe he could take G-Man's punches and outwork him to capture a close decision
Ugotabe Kidding is on crack. McClellan was a relatively basic fighter but he is MUCH better than Chavez. Chavez would get flattened, he's never taken that kind of shot in his life. Jackson would murder Chavez too.
McClellan was an overrated piece of human garbage, but he was a hell of a lot more proven than Chavez. I can't picture a guy like Rubio (Chavez's best opponent!!!) doing anything other than getting decapitated against him