Yeah, McCallum beats the absolute living fuck out of Cuevas. And I doubt it'd take even 6 rounds. At 154, even Duran did it in four.
Yeah, Cuevas is just triple fucked here. 1. McCallum was just a different level fighter. 2. McCallum was too big. 3. The styles highly favor McCallum.
I don't know what would happen if McCallum had to make 47, but Cuevas was just going through the motions at 54.