It seems to be such a huge advantage to have the resource to train the entire navy and airforce without losing a drop of oil. By the war break out USA could simply field the most advanced trained ships with the all doctrine and sprite researched.
But they did have a large navy that was able perform training and maneuvers as needed and wasn’t constrained by fuel, prior to the war.
historically, the navy as opposed to the army, stayed staffed up and had continued ship development during times of peace.
you don’t typically have enough mils prewar to build up a large air force, so I kinda think that’s moot—but I don’t play vanilla so it could be more egregious there.
And beyond all of that the us is already woefully less capable in game than irl.