Rather than batting order (same batting order won us last match), I would say, it's the bowling that cost the match.
*Chahal-Kuldeep combination proves nemesis for Australia, that shouldn't be broken in the series.
*Both Shami & Umesh shouldn't be chosen, both of them were out of match practice. At least one from Bhuvi & Bumrah should play. Rotation should be done wisely, not just to give chance to bench.
*Umesh & Shami's last 2 overs cost 28 runs. Can't surely say, Bhuvi-Bumrah would cost less, but chances were high. M.Clarke continuously repeated throughout his commentary about the difference of 290 & 334. Allowed Smith to take the chance to bring Zampa in front of Pandya.
Coming to batting order; Yes, Pandya and Pandey's order should be reversed. The role Pandya does at 4, can be done by Pandey. But Pandey can't do Pandya's job at 7 (hitting from the 1st ball).
IMO, the order should be:
1. Dhawan/Rahane (Rahane can only be considered as opener in the absence of Rohit/Dhawan, he is a waste in 4/5/6).
2. Rohit
3. Virat
4. Pandey/Rahul (Rahul is my personal favorite in this position)
5. MS (He needs some time to settle)
6. Kedar/Raina/Yuvi
7. Pandya
If 2nd wicket falls after 35 overs, then no.4 & no.7 should be switched.