We both know "bodybuilding genetics" = being able to endure boatloads of drugs without keeling over, so it definitely exists.
I'm not sure if I myself could do it without dropping dead in the first 5y
Sure, though most everyone will survive that first cycle which will tell you if there is
even a slight chance of some day becoming competitive a pro. You can pretty much tell after a few weeks if the muscle bellies and drug response is there.
Billy Guns doesn't have it. Goodrum doesn't have it. They might have the drug tolerance though. Billy Guns didn't seem to suffer major sides despite massive drug intake.