A man such as Arnold, with a large bone structure would possess much larger muscles at the same body weight as man with a smaller frame. I have seen this in person. Having met Arnold, Draper and Zane, I can definitely state that Arnold and Draper were both men blessed with above average skeletal size. Zane's frame was of course much smaller but he still built one of, if not the, as many hold true, best physiques ever.
Another example of skeletal superiority would be the size and shape of a man's rib cage. Both Arnold and Mike Katz each had large, one might say, "voluminous" rib cages. This would give them an advantage in building pure chest size at any given body weight. Just look at all the talk of "small" clavicles here on this board and you'd be hard pressed to deny the logic behind the truth of a skeletal foundation. While it does seem that GH helps to alter or even grow one's skeleton, what nature has given men like Arnold, Draper Katz, Ferrigno and other truly big men cannot be denied.
Many talk of muscle belly length and the like and that is also a contributing factor to overall muscular size but the foundation upon which all that muscle must be built must be capable of supporting greater than average size and strength. Small joints and muscle insertion points are genetic factors too, but again if you have a skeleton like a small bird ("AHEM"!
) its highly unlikely you're ever going to approach the size of the Oak. Vince Gironda used to say "Train for shape and size will surely follow", but only to the extent allowed by your framework.
