Uhh... the Ki45 was a recon plane for the beginning of its life. It started with 2x 7.xmm guns, and when it was upgraded later with the big gun, one of the 7.xmm was removed. My source states that the upward firing tuns are 12.7mm, NOT cannon. Relatively FEW ever got the forward cannon.
These planes were ineffective everywhere, and were NO threat at all until they were used for kamikaze attacks, and then their only threat was non-fighter-performance related. The cannon-armed variant was a night fighter against B-29s, intercepting bomb raids at night and running kamikaze attacks during the day. This plane has NO role in the current setup, in my opinion.
By subbing the 110C with 2x 20mm and 4x 7.xmm, I think there is a BIG difference than a single big-bore gun with limited ammo and a bank of 6 standard normal powered guns with thousands of rounds of ammo. Not much of a comparison, if you ask me. 110c blows the ki45 out of the water in any situation, unless the ki45 is a kamikaze and the 110 is behind it (then it might outrun it, just barely).
Bad matchup in my mind. Not in any way similar, considering roles, performances, firepower, and capabilities.
Leave the 110c out.