To get the ball rolling more on suggested different balance of planes, here is one among many possibilities.
This set:
-- reduces 190's as per Devil's comments to be more realistically proportional to 109's,
-- increases the P-38/Spit ratio (as is likely also more realistic), and
-- makes P-40's+P-39's equal to number of C.202's (balancing the lowest-performance planes on each side).
The non-realistic aspect is that the proportion of P-40's is much lower than history, which is this case's sacrifice to playability.
Fighters
P-38G, 24
Spit V, 12
P-39D, 6
P-40F, 8
Bf 109G-2, 15
Bf 109G-6, 15
FW 190A-5, 6
C.202, 14
Then, to make the bomber mix more even as well -- basically half the US force worse than Ju 88's and half better.
Bombers
B-25C, 7
B-26B, 4
B-17G, 4
Ju 88A-4, 15
What do folks think of this?