I don't think it's a foregone conclusion at all that Sergio Oliva would have been absolutely superior to
everyone in later decades, with more "science".
I know it's blasphemy to say something like this, but I think he would have been like a Paul Dillet if he competed in the 90s for example. Sergio seemed to have a bloofy look which is somewhat genetic and the back wasn't that great. I don't think he could have beat Coleman at his best, not Dorian, not Kai, probably not even Haney. This is just my opinion/hunch and impossible to know or prove.
He competed later on and yes he was old in 84 or whatever but his physique still looked fresh and despite being in good condition, better than his early years, he couldn't come in the top.
The fibers, attachments in his back aren't there to the level of a Coleman or Yates