arnold could never equal ronnie on size and conditioning
could never? I'm not sure if this is just bad grammar or what. If you mean Arnold never did equal Ronnie on size and conditioning, well of course, they were in different eras with different drugs. If instead you mean if everything else was equal, Ronnie would still dominate Arnold, then you don't know what you're talking about. Compare Arnold at 16 with Ronnie at 16. They were either both drug free, or pretty close to it. Arnold was the better athlete, had the better physique when they were in their teens. Compare Arnold and Ronnie when they both only used steroids. Arnold would dominate. Compare when they both used GH, Ronnie would dominate, but that's because he was still an up and coming bodybuilder, and Arnold was making billions of dollars for the movie studios. Compare Arnold and Ronnie were doing gh and insulin and a whole bunch of other drugs. Whoops, Arnold never used the current drugs, at least not in any significant way.
To put it another way, what makes an athlete tops in his field? Genetics, knowledge, resources, and drive. Ronnie has the bigger physique because of better knowledge and resources (better drugs, better ways to use them). Arnold is one of the most driven persons in the world. And Arnold had incredible genetics. If a young bodybuilder with Arnold's genetics and drive were to take all the drugs Ronnie has taken, there is no reason to think he couldn't accomplish just as much, if not more.