Its very interesting, this debate about Warne and McGill.
McGill does not have Warne's control nor his variation. To that extent Warne is by far the superior bowler. Having said that, there is one facet of McGill's bowling which I have always found lacking in Warne.
McGill is an attacking bowler like all orthodox leg spinners have been over time. His line and length are meant for attack. He bowls on the middle and off or outside the off stump (by and large) and pitches up enough for the batsmen to have a go at him by trying to drive him through the off side.
Shane Warne bowls a middle and leg stump or outside leg stump line (by and large) and bowls a length which forces the batsmen to play defensively off the front foot to him. This is a defensive mode of attack. That is why, when batsmen use their feet well, as the Indian's do, Warne is so much less effective.
I have always felt that Warne would have been a greater bowler if he had bowled a traditional line and invited the batsmen to drive.
It was fascinating to see how MacGill got his wickets as the batsmen went to hit him and Warne got his as the batsmen struggled to keep their wickets intact.
With Warne's control, he should not have become the defensive bowler he has. I think we have been denied a great contest between say Warne abd Tendulkar or Warne and Dravid by Warne not encouraging them to hit him through the covers of the front foot. I firmly believe that had he done so, he would have performed better against the Indians that he has done so far.
An opinion...just an opinion.