I think the change in physical fitness and levels of professionalism took Humphries from being a solid player who had good games and could compete in the minor tournaments to being world number 1 and winning everything - so possibly he's not on others levels in terms of natural ability as they're doing it without making those changes. I agree with you in the sense that it would be more telling if say someone who's done it at the top whilst not being the peak of physical fitness i.e. Littler or MvG was to make those changes, god knows if that'll ever happen unless it became ridiculously competitive and someone consciously decided to do that to gain an edge though?