Japanese tanks were shittiest ever, more shitty than shermans and every tank from WW2 you can imagine (except maybe from german satelites country's tanks). So it will be verry hard to fit japanese faction into a game were tanks are so important. More than this, Japan didn't have effective AT infantry. They were good at planes, ships, artilery. That's all. They would fit into a scenary that would involve alot of water. Like battles for islands and peninsulas.
And no, COH2 doesn't need more factions.
When COH3 will be issued, they can focus on Pacific war. That's were they fit best. But tbh, I would like COH3 to be focused on Afrika. Afrikakorps, italians, british and americans. That's a theater where 4 factions would go verry well both from balance and historycal point of view.
Agree, but Italians have shitty tanks as well, unless they will focus on defensive AT emplacments like 88s, and elite inf.