Unlike Ruiz, Foreman would fight aggressively, he wouldn't become tentative because he missed a few punches by a mile. Also Foreman fights physically , he'd "bump" and "push'" Jones.Jr at every opportunity. The physical tactics would eventually wear Jones down, allowing Foreman to ko him.
My mind automatically went to 70s Foreman. Would b a fun fight on Undisputed but for a hypocritical irl fight not for Roy! Can see this as a replay of the Moorer fight honestly. A heavier Roy is still fast but more hittable than him at lower weights he was comfortable at pre Ruiz. He'd befuddle Foreman but again all it takes is one clean hit no matter how long Roy is able to survive for the moment. A more patient Foreman makes the odds of a longer fight happening too.
There are a fair few variables, but i think it boils down to the fact that Roy can't hurt George, but a big hook from George would massacre Roy.
Roy Jones may be one of the greatest ever, but if you catch him and hurt him, you can beat him All George has to do is land a few at his body to cripple him This isnt John Ruiz
If Tommy Morrison could outbox Foreman I could see Roy Jones doing it. Not necessarily sure he could do it but it's possibly.