Agreed, the Ki-43 (multiple versions please) is a particularly large hole in the planeset.
That said, since AH2 was released, 75% of new Axis aircraft have been Japanese, the Ki-84, G4M1 and A6M3 against the Bf109G-14 for the Germans and nothing for the Italians.
The Allies have fared much better with the I-16 for the Russians, the Spitfire Mk VIII, Spitfire Mk XVI and Mosquito Mk XVI for the British and the B-24J, B-25C, B-25H, B-29, F4U-1A, P-38G, P-38J, P-39D, P-39Q, P-47M and P-47N for the Americans.