I agree with Kweassa, not because I think the Ki.84-I-Otsu would be bad for the game, but rather becase six times as many Ki.84-I-Kos were built.
A larger percentage of Ki.84s were equipped with four cannon than WWII La-7s were with three.
The two 20mm cannon, two 12.7mm machine gun Ki.84-I-Ko would be much more representative, and so should be the one added.
(Of course, HTC did add the very unrepresentative F4U-1C as the first Corsair)