This is only an aesthetic suggestion. With so many nations, many designs of similar units were different from one another. The game represents this with American, German, and soviet 'skins' for units. However, I think this can further be improved with French, British, and Italian units, as well as other nations who also designed their own weapons of war. I am certainly unfamiliar with the difficulty of implementing such a change- I imagine it to be quite hard- however I think it would generally improve the player experience.