Hey someone who gets it !
Presentation was even more important. Worst thing about Sergio was that he hardly ever flexed his whole body and especially his legs were unflexed most of the time, in the 72 Olympia he was very conditioned not only by his standards but there is hardly one pic from that contest where this can be seen. In comparison Arnold was always flexed from top to bottom. Arnold said himself in an interview in the 70ies that presentation was what held Sergio back the most, also Serge Nubret. Sergio did not even get the posing oil right most of the time !
Apart from that imo Sergio did not really have the persona and marketability to be chosen over Arnold in a narrow decision from 1970 on and that's another reason why he did not win the 1972 Olympia where it seemed that even Arnold himself lacked his usual confidence next to Sergio, very easy to see on the video. The Olympia from then on was always about dinasties and I think nobody can deny this. Not about black or white, but consistency in who is the top man in the sport and about the image he projects. So as long as the the top man returns the next year with decent conditioning and shape (an lately at some points not even that) the title is usually his.