VansCrew obviously needs to read a lot more about Japanese aircraft.
For example, the Ki-44 and J2M are both interceptors with good climbing and diving performance, but average turning capability.
The Japanese fighters we already have do not match his claims, the Ki-61 being quite good at diving and the N1K2-J performing well too. The Ki-84 dives fine as long as you don't overspeed.
As for guns, the Ki-43-II has two 12.7mm guns, the Ki-44-II has four 12.7mm guns, the J2M3 has two 20mm Type 99 Model 1 cannons (as on the A6M2) and two 20mm Type 99 Model 2 cannons (as on the A6M5b and N1K2-J), the J2M3a has four 20mm Type 99 Model 2 cannons (as on the A6M5b and N1K2-J).
And once again, we see that the Japanese fighters in AH do not have identical armaments other than the Ki-61 and Ki-84, and even there the positions of the guns are reversed.
A6M2: two 20mm Type 99 Model 1 cannons and two 7.7mm Type 97 machine guns in the cowl.
A6M5b: two 20mm Type 99 Model 2 cannons and one 7.7mm Type 97 machine gun and one 13.2mm machine gun in the cowl.
Ki-61-I-Tei: two 12.7mm Ho-103 machine guns in the wings and two 20mm Ho-5 cannon in the cowl.
Ki-84-Ia: two 20mm Ho-5 cannon in the wings and two 12.7mm Ho-103 machine guns in the cowl.
Moving on from that, the performance of the different Japanese fighters in AH vary greatly. The A6M can kill Huricanes and Spitfires by turning with them, if the Ki-84 tries that it most likely dies.