Looks like on balance the Japanese have the edge if you go by the stats.
The P-47D-11 has 147 kills and has been killed 126 times against the A6M5b.
The P-47D-11 has 215 kills and has been killed 259 times against the Ki-61.
The P-47D-11 has 82 kills and has been killed 73 times against the N1K2.
The P-40E has 33 kills and has been killed 76 times against the A6M5b.
The P-40E has 52 kills and has been killed 106 times against the Ki-61.
The P-40E has 22 kills and has been killed 52 times against the N1K2.
The P-38L has 48 kills and has been killed 48 times against the A6M5b.
The P-38L has 41 kills and has been killed 47 times against the Ki-61.
The P-38L has 76 kills and has been killed 93 times against the N1K2.