Hopkins had it tougher in the fact that he didn't have the size advantage vlad had. Vlads dominace was based on size. Hopkins was based on knowing how to fight. Not a big Hopkins fan. But I think Hopkins fought tougher opposition.
Why is being big a quality to be discounted? Some people are naturally big the way some people are naturally fast handed or fleet footed. Why are you considering one somehow less valid than the others? It makes no sense.
I'm just saying only in hw can you have such a significant weight or size advantage. Most weight divisions fighters are within a few lbs of each other.