Why the Indian Ocean coalition's diversity was not its main weakness

Did the Indian Ocean theater's greater cultural diversity make allied command less effective?

Not primarily. Compatible command systems worked, while recently raised troops and earlier diversions to other campaigns created the larger problem.

The Indian Ocean coalition included troops from varied cultures who mostly worked within compatible British command and training systems. By the time major offensive operations began, these formations could fight effectively together. Their early weakness came from newness because prewar and experienced units had already been drawn toward the BEF, Iran, Iraq, Somaliland, and other emergencies. Southeast Asia therefore received formations that needed time to organize and train. Force generation and prior commitments explain more of the early difficulty than cultural diversity does.