Ryback is FAR bigger than Goldberg. I don't see how a 240 lbs guy is supposed to be stronger than a 290 lbs guy, unless either one of them was a powerlifter, which Goldberg was not. Doing a Jackhammer and a Fallaway Slam are not the same thing anyway.
Ryback : 6'3, 290 lbs ; Goldberg : 6'4, 284 lbs.
And force is not linked to your mass, weightlifters are stronger than bodybuilders.