One thing that has become painfully clear is that on all fronts different countries and even different commanders working with each other are very much having issues cooperating with each other. The Germans and Italians, the British and Americans, Stalin and his commanders, Japanese command structure all share one thing in common in that there are trust issues and lack of faith within their own command structure.
The allies do reach a consensus but training with each other and learning new tactics from the other but still the British lack confidence in their American counterparts as the British are battle tested while the Americans are not and a lot of friction existed between both throughout most of the war.
Then the Germans had little faith in the Italians who had very good and well trained soldiers but lousy leadership. The Soviets had Stalin who didn’t trust anybody and routinely had his commanders killed. And finally were the Japanese where the navy, airforce and army hated each other and often refused to cooperate with each other.
Hard lessons were learned and it showed that a structured and integrated command structure was key to success. Scary to think how fractureD all command structures were during the war and it often was a miracle anything got done.