Probably. I still think Bute looked good for most of the fight. He is physically bigger than both Calzaghe and Kessler. Having said that I find it disgraceful that andrade didnt get his belt with him to California.
Bute was impressive, but not in the way Kessler was impressive against Andrade. That said, Bute is 6'3", and doesn't even look weight drained, which is amazing. By virtue of his size alone, he'd give Calzaghe and Kessler difficulty. Plus, he has good movement and speed.
The stamina issue is a real one. Calzaghe would have made Bute work more than Andrade. But it was very strange. He looked great in the 11th, and then just wilted in the 12th. I was thinking 'huh?' at the time, because there were no signs of fatigue preceding that.