Arnold was not that strong as people make out. See him off season his muscles vanished. Dianabol & volume he pumped up again. With So much volume you can't lift super heavy. Might have done a few ego Lifts with Franco but even Franco Was stronger than Arnold.
He never had the stocky bone structure for it. Look at Arnold's slender wrists and long muscle bellys.
He was alot like Levrone imo but had more heart and bone headed determination than Kevin.
They could stop training for 6 months pop some diana train volume for 2 weeks and be ready to step on a bodybuilding stage.