In this post, I will address the issue of customizing British pilots and American tank crews
British Pilots:
British pilots in Tunisia and the Ardennes have a blue uniform in customization, but it is missing in Normandy, although it was the uniform of British pilots in Europe in reality
In the Ardennes, pilots should have the same blue uniform but with a jacket, you can even give them an American jacket if you’re too lazy to make a new one
American tankers:
American tankers wear boots by default
but many in Europe wore these boots with gaiters
there are these leggings in customization, but I want to wear gray or green pants instead of just brown ones
And in the Ardennes, for some reason, they wear pants with boots and leggings, and they don’t get cold?
Give them winter pants and boots, American infantrymen in the Ardennes have winter uniforms, but tankmen don’t 
Addition:
Add goggles to the M-1938 helmet in customization
And a regular M1 helmet
Also recommend checking out the post about the problem of customizing British tankers