I returned to this sculpt after being busy on other stuff and it suddenly occurred to me "his head is tiny and those horns aren't going to scare anyone or do any damage. Once again Dynamesh enabled me to make changes that might have taken time in the past. Now he has a serious set of horns and a head in correct proportion to a man being inside the suit. I've also figured a way for the face plate to slide up to reveal his face for the classic Rhino look.
Onward with the sculpt....oh that's the end of lunch :-(