The Tony is in no way an equal match for corsairs or hellcats. It's not harmless, but it is outclassed severely in every regard compared to the F4U-1A, and most ways to the F6F-5.
EDIT: To add to that, I hesitate to add the Ki-84, because it is leaps and bounds beyond the A6Ms and Ki-61s that it's filling in for. IMO the Ki-84 will be the uber plane to beat in the matchup, and that doesn't fit. The N1k2 I can see -- its performance and handling are more in-line with the Ki-61. I also think that the A6M5b, while slower, is quite capable and a lethal enemy due to its cannon setup and its maneuverability. I think it's really undrerepresented in the setup and should play more of a role.
In the spirit of balancing the gameplay, I understand certain compromises must be made. However, I think you've pushed the Japanese side too far to "end of war" and left all the actual planes out of it that were there. Might I suggest that the compromise goes both ways? Push the US planes backwards a little and ease off on how many Ki-84s are in the list? Bring those Ki-61 and A6M5b numbers up, but drop the P-38Js down to P-38Gs perhaps. Drop those F4U-1As down to F4U-1s, and maybe only have one squadron of them. Swap in a second squadron of the slower F6F-5s. I'm not saying to swap them out for FM-2s or anything, but we can ease back on the US side rather than ramping everything up on the Japanese side.
What do folks think of that? Because I love the Ki-84. I really do. It's just the best end-war plane in the Japanese planeset. I really don't think it belongs in a Rabaul lineup unless in limited numbers. Currently? It's the majority of the roster.