There's absolutely no reason to believe, outside of a punchers chance, that Tyson could see Ali in the ring. Ali had every skill and attribute that we've seen could frustrate Tyson and negate his punching power. Ali was a FAR superior boxer than the best boxers Tyson ever faced (Lewis and Holyfield), and both of them owned Tyson.
We all saw in the Buster Douglas fight how much intimidation was a part of Tyson's dominance, but Ali would not have feared Tyson any more than he feared Liston, Frazier or Foreman, who were three of the most feared fighters ever.
Ali's jab, footwork and power (not equal to Tyson's, but still impressive) would all have frustrated Tyson and kept him from closing often enough to go to work and tee off the way he liked to.
This is no contest - I think Frazier was a tougher opponent for Ali than Tyson was, because Frazier could TAKE punishment as well as dish it out.