Leg spinners haven't found much success in Australia?
lol Australia is always known for it leg-spinners. Are you unaware of the cricketing history? Australia have produced imo the three of the greatest leggies the world has seen. Grimmet and Bill O'Rilley are the others. So clearly you are lacking knowledge to say leg-spinners haven't had much success in Australia.
Murali did struggle against India, then what about Warne? He struggled even further.
Murali's overall record vs India 105 wickets at an average of
33
Warne's overall record vs India 43 wickets at an average of
47.18
Bowling records | Test matches | Cricinfo Statsguru | ESPNcricinfo
That's a massive difference. So once again your logic is flawed. Warne obviously struggled against India due to their quality Indian batting.
Murali on the other hand had fared way better than India.
This imo is the best yardstick to compare the two spinners. How they fared against quality Indian test batsmen