I don't think there's a great difference between five runs per wicket. Warne's also a type of bowler more inclined to get wickets faster than Kumble (although I'm not going to bother and see what Warne's strike rate was in 2004 and what Kumble's generally is).Kumble averages 24.73 in India.
[edit - I don't want to get pedantic and turn this into something akin to a Warne v Murali debate *shudder*]
Nah that's a complete myth. If you can't tell Warne's form was poor in India in 2001 then something's wrong. His accuracy was way off. I remember in the 3rd Test of 2001 Steve Waugh went to Warne for a miracle and Warne bowled two of the worst flippers you'd ever seen and got punished each time. Warne was such a liability that his very brief spell in that second innings was the reason that match didn't go down tot he wire. Australia got 7 wickets, if I recall, in that final innings. Had Warne not have bowled things could have been different.The reason Warne didn't do as well against India is because his method of bowling plays right into Indian hands. He didn't do much of note in Australia either, against India.
There's no logical reason to suggest Warne's method of bowling was wrong because Indian's don't have some magical batting technique that's any differnt to any other professional player. Indians typically are good confident players of spin and that's part of the reason why Warne wasn't successful in India. But this myth that you can't bowl a leg-stump line to Indians is ridiculous. I've seen Warne dismiss Indian batsmen when he puts the ball in the right spot and does what he does well. Hell he bamboozled the life out of Rahul Dravid in the World XI game in 2005.
Warne simply didn't bowl to his best. If you couldn't see that he lacked accuracy, fitness and confidence then there's something wrong.