Arnold's upper legs were sometimes a little weak when compared to his upperbody. His left arm, in some shots, looked smaller when compared to his right arm - speaking from a straight-on shot, not a twisting shot which purposely made the left arm look smaller. In some shots, Arnold's triceps are disproportionate to his biceps and hamstrings looking disproportionately smaller than quads - most notably in the side chest pose. At the 1968 IFBB Mr. Universe, his conditioning was horrible and he could have been alot bigger at the 1980 Mr. Olympia.
Sergio also had his flaws. Disproportionately small biceps, coupled with long biceps insertions and lack of detail between biceps and triceps when viewed from the front and back. Before 1980/1, a lack of detail between the muscles of the upper back, particularly in the back double biceps. Arnold always had great back detail and beats Sergio at the 1972 Mr. Olympia, because of superior detail and posing ability in this pose.
Make no mistake about it, though, Arnold had a very thick back and could match Sergio for thickness when they were competing together in the '70's.
I think that some of the standard suppositions about these two are incorrect.
In the case of arms:
Arnold's triceps are to this often considered weak. In fact they were quite well developed with good size, it was just (1) the outrageous bis and (2) the lack of great cuts that left them less noticed actually-very similar to Coleman. They both had the same thing, outrageous bis and large but less than great triceps cuts thus the tris were overlooked and deemed to be out of proportion to the bis, which i would say in both cases was untrue.
In Sergio's case it was the opposite-bis were quite large, but (1) overshadowed by outrageous tris and (2) the lack of much biceps detail, thus the assumption by some that the bis were undersized or weak when they weren't.
In the case of hamstrings, while Arnold's were poor that was true of most BBs at that time, thus it wasn't a big issue IMO.
In the case of Sergio's back, i'm not sure i agree that detail only came in during the early 80s-i think that what that was was an absence of pics taken of him in peak condition, given that by then he wasn't with Weider anymore-see the next paragraph. Also, he wasn't in great condition alot of the time, which compounded the issue.
The unfortunate thing about Sergio and any non-IFBB BB in the 70s is that the photography in most mags outside of Weider's wasn't great, thus there aren't alot of great contest and training shots of Oliva, not nearly the same number as readily seen with Schwarzenegger, which tends to tilt the bias in favor of Arnold, given the far more numerous and high quality pics available of him in his prime.
