I agree with Mustard that it would have been interesting to see Lendl , still to win a major, against declining Connors.
But bear in mind that Lendl amde an enormous menthal effort against a man that had whipped the floor with him in all his former matches that year and was stil doing two sets at the famous RG final.Lendl had to overcome NOT ONLY MAC´S BRILLIANT PLAY but alos, the fact that Mac had beaten him handily at Phily,Masters,Forest Hills (ˇˇ on clayˇˇ), Dusseldorf ( ˇˇ on clayˇˇˇ), Brussels...and was two sets up.1981 or 82 Lendl would hace surely yielded and Mac would have easily win a straight sets final and would have his RG title by now ( and would inmediately be considered a GOAT contender).
But Lendl refused to yield.
IMO, it is much more difficult to overcome that deficit against 1984 Mac ( with all the former defeats I mentioned) than beat a declining Connors, whom Lendl ahd thumped in their former matches (Masters,Rotterdam,WCT Tournament of Champions), even if Connors had had in the past the menthal edge over Lendl.
In other words, a declining ( yet dangerous ) Connors would have almost no chance to win the 1984 RG version of Lendl on clay.He was still better on grass and about even on hard, so a 1984 USO final between both would have been a great match to see ( and I think Lendl would´ve won it, finally)