Ward. Too big, too tough, too dirty. He'll manhandle SRR, grab his knees, hit his nuts and find a way to impose his size in the ugliest of ways in addition to working over the body. You'll get flashes of SRR getting combos off etc but in the main Ward will break his flow and grind him down until the late rounds are all Droopy Dawg.
I'm going with Robinson to outbox Ward. He was too fast and nuanced. Ward's best wins were against stationary targets, fighters who stood right in front of him, and he still fought dirty.
What weight? Ward wouldn't make MW with same day weigh-in, and at 168 or 175 with day before he'd have 20 lbs or more on Robinson in the ring. That's a lot of weight to give up to such a good fighter even for the GOAT.
Traditional catchweights, which means each man comes in at his best weight? Andre easy. Too big, too much.