I'd always doubted the way he uses bands and overload work in his gear but I'm starting to see value in it for building the forearms since mine have started to become my weak link......
As for the short arms and big chest - I'm sure he has fair genetics but a lot o that is how he's built himself over the years. That build doesn't happen on accident. Also, from years of heavy presses your forearms will bow. That's not conjecture or bro science, that's from my MRI.... We thought I had fractured mine on a 950 press and when we did X rays we found that my ulna is straight but from years of micro fractures and calcification the radius has curved and both are ( in the words of my ortho) "twice as thick as a human's"