I think this could be a very interesting fight, especially if we are going to assume that Toney comes in motivated, in shape and determined to win. In that case, he would be plenty aggressive. I just watched the Holyfield fight, and Toney went after him and got that ass; he toyed with Evander from the second round on.
One thing you aren't going to do is dance around James Toney and poke at him with a jab, or beat him with the right hand, and Ali had nothing else. Ali really had only reflexes and conditioning, and that is plenty against the big dummies of the boxing world, the HW division. Not so much against a very smart fighter.
I think that the jab Toney showed in the Hembrick and Holyfield fights, for example, would give Ali troubles because when Ali jabbed his right glove flared out; it didn't stay home to catch the counter jab. Norton exploited this, and I think Toney, much more skilled and faster than Norton, would be able to do the same. Ali would have a lot of trouble because Toney would be as fast ands would be able to counter him.