On the topic of head being dropped, I see nothing wrong with the call in a vacuum. Mcdonald indicated that head would likely not start the series in an interview earlier in the Aussie home summer. He averaged sub 20 across 50 test's in the subcontinent earlier this year and there's been no significant change in his technique to indicate that he's suddenly gonna start making runs in the subcontinent vs decent spinners. He made home runs vs a good english attack on some absolute seamers at a high SR the summer before those subcontinent tours in 2022, just like he did this summer vs Windies and SA before the India tour.
With that in mind, if we where gonna drop head for that reason, warner probably deserves the axe as well. Even with that double hundred vs SA earlier this summer he's averaging 30 odd since the last ashes in AUS and looks nowhere near the player he was at home pre 2020, also has never made consistent runs vs Ashwin, home or away, or runs in the subcontinent for that matter, since the 2015 tour of bangladesh. I'm inclined to think warner may not have started this series if Green was fit, with renshaw opening and handsomb at 5 over head, but thats conjecture.