i do not agree with the "heavier = more mass" part.
Ronnie had tremendous genetics, if for nothing more than his response to gear - doesnt get any better than that.
If heavy weight was the key to being giant, nobody would train light. i wouldnt consider lee priest, dexter, shawn ray, etc etc to be big and "thick" as ronnie, but they are by no means small, and they dont train nearly as heavy as ronnie's big ape ass does.
I could name 10 bodybuilders that have better arms than dorian, and they didnt go all heavy stupid crazy, just high volume and moderate weight.