Actually, I halfway believe that could be the case. I don't think that Manny looks at himself as a macho guy, he looks at himself as more of an entertainer.
I have no idea if he ever, let up on the gas out of compassion or any other reason, but it would not surprise me. He always talks about giving the fans a good show or a good fight.
Manny doesn't strike me as the kind to take pleasure in beating someone for the fun of it.