Mitchell Marsh needs to score runs in shield first. 

Tis sounds obvious, but the number 6 spot should first and foremost go to someone who can bat at 6. Mitchell Marsh has not shown himself to be capable of that in red ball cricket yet. 

If an all rounder fills that spot it should be a "batting allrounder". Otherwise pick a batsman. 

So is James Faulkner.

Given Maddinson has failed at every opportunity, the bowling all rounder is needed, possibly batting at 7.

With the keeper issues  being paramount in India, I think Nevill should be reselected as he is a better keeper. He played an amazon innings in Hobart in the Shield.