Speed kills, and from what I've gathered, SRR was at least as quick as Jones and much more skilled. James would go the distance but he wouldn't know what hit him, size doesn't play much of a part imo. Also Toney was better in 91/92 imo.
I see Robinson at his (middleweight) best winning a decision over the lackadaisical Toney, who would at this point sometimes only fight for 1 minute a round. It wouldn't be easy, but Robinson showed how he fought against a similar mover in Turpin, who was also physically stronger. It would be a varied, slightly different combination of the first and the rematch IMO.
Robinson's superior speed and mobility would be the big factors here. He could keep Toney on the outside and box him for 15 rounds without too much trouble. Jones managed to do that against Toney and while I can't be sure that Robinson was as quick as Jones or as good an athlete, he was fundamentally better in terms of technique. Toney would spend a lot of the fight needing to reset. As has already been pointed out, Toney liked to take rests during rounds. That would cost him as he would need to apply continual intelligent pressure to make some headway. I don't think he could do that. Robinson by clear UD.
I do not like the comparison to the Jones fight as Toney was not in shape there.That being said, I take Robinson by competitive decision.
Yup but a tougher fight than many think. Toney was not just a great fighter but a defensive wiz with an amazing chin.