Probably the Japanese tank that would fit into AH best would be the Type 97 Chi-Ha.
Armor: 8-33mm
Main Gun: 57mm Type 97 w/100 rounds
MGs: 2x7.7mm (coax & rear)
Speed: 38kph
Production: just over 2000
Also a later version was the Type 97 Shinhoto Chi-Ha which changed the 57mm for a high velocity 47mm with 120 rounds.
This tank could be (let the screams ensue) a sub for the Italian M13/40 & M14/41 (
maybe the M 15/42 also) in scenarios. Yes, I know the Italian 47mm was superior & had more rounds, yes I know the Italian tanks had more MGs, yes I know the Italian tanks had better armor, yes I know the Italian tanks were slower. That is why it is not an Italian tank. Of course we could always sub a M14/41 for the Type 97 in scenarios also.
I'd rather get the amphibious Type 2 Ka-Mi for the Japanese and the M14/41 for the Italians; but I'd rather get 1 new plane & 1 new tank over 2 new tanks.