Note
Ki-61-II Kai (with 2x 100kg) should be moved to Battle Rating III since its not better than P-51D
The bit better Ki-100 with 2x 250kg bombs would be more suitable Battle Rating IV candidate.
Honorable mention that nearly made it into the Top 5
Ki-67-Ib — Battle Rating V
Bombload Options Configurations [Late modifications had wing pylon mounted bombs as well]
5x 250kg (3 in bomb way, 2 on wings)
3x 500kg (1 in bomb bay, 2 on wings)
1x 800kg + 2x 250kg (1 in bomb bay, 2 on wings)
1x 500kg + 2x 250kg (1 in bomb bay, 2 on wings)
Since the Kikka was added with 1x 500kg and it can replenish bombs fast, it made the Ki-67 no longer a priority addition.