Ashwin is not a leggie, perhaps they need to develop Kuldeep for this role. But by sending him back mid-tour after one tough game isn't going to help his confidence grow any bit! Probably something else (seniority, favoring, etc) prevails more in the team management more than skills!
Pandya can play in Australia provided he improves his batting & is more consistent, but he just scores a fifty in 5 innings, he is going nowhere!
Do you think the following XI can do any good in Australia?
Prithvi Shaw
K L Rahul (one last chance as there are no other options on flatter Australian pitches)
Pujara
Kohli
Rahane
(a proper No.6 batsman who can bowl some finger spin)
Saha
Kuldeep
Ishant
Shami
Bumrah
(Bhuvi should be in the squad. Also another specialist opener & backup batsmen!)