That's around 682lbs.
You must be one strong mofo to say "only" 310kg.
And did this video show him going to complete failure, was there a reason he went "just to parallel" (did you know his exact goals and training history at the time)?
Yes, bodybuilders are relativley strong compared to just about every other athlete, but their goals are different and I'm sure Mariuz would kick Ronnie's ass in a strong man contest, just as Ronnie would beat Mariuz in bodybuilding (notice how I didn't say 'kick his ass').
I really don't see how you are justifying that Ronnie is "a hell of a lot stronger in the legs".
Do you have a link?
I know to you it's "only 310kg", but personally I think that's a whole lotta weight and I'd love to see it.