Can I suggest Chindits, 14th Army and WW2 Australians to the list of possible additions, cheers
You can get 14th Army and Chindits out the existing ranges of WW2 in bush-hats. Since the troops in Burma also wore the steel helmet you can use them too. Main ommissions are Indian troops in turbans, although I have reason to believe they also wore the helmet in action.
I have seen pictures of Turbaned Indian troops with netting over the Turban to add camouflage
I think the turban in action depended on religious beliefs - some wore it for that reason but I believe those without such a reason switched to the helmet.
I bought the WW1 indians, and the indian vickers MG,s. The miniatures are older and more rigid, and the webbing isn´t the correct one, but you have the turbans and the beards... so they look great in an East Africa Campaign
Greetings
In action turbans would pretty much be Sikh units in WW2.
Other units e.g. Punjabis might wear (different) turbans out of action.
Regards
Edward