Well done Kakitof you have proven you know nothing about the Japanese Army. How did they manage to almost half of China and most of South East Asia? With ships and aircraft alone?
Look up on how they took the British fortress on Singapore and you will see how pivotal Japanese infantry were...
The Japs took the underequipped and badly managed Commonwealth garrison of Singapore with a bunch of soldiers on bicycles and 50 light tanks. Equipment used in that battle wouldn't come close to stacking up to anything used or seen in COH2 by other factions.