[Mobhack]

Oppose the Japanese with stuff they cannot easily counter. The US Stuart tank is excellent against them at short ranges - not just for the 37mm HE, but the 3 other MGs. It also deals with their tanks just fine. If Russian, the T-60 with its 20mm that has a 1 hex blast radius and a decent supply of HE is a good choice. Both are cheap. Bren carriers, with a scout team on board to spot that do not get too close or dismount can provide useful armoured MG support and spot better due to the infantry passengers carried (so should scout alongside or just ahead of your tanks). The M3 mediums are not brilliant versus the Germans, but are battlefield queens in the Pacific - if there is a CS version available with more 75mm HE in your OOB, use those. Shermans and T-34 are overkill, they are like far Eastern "Tigers". Just try to keep armour 2-3 hexes away from enemy infantry.

If you have good fields of fire, MMG and HMG sections following up your infantry are good, especially if fired at clusters of Japanese infantry that have bunched up due to the blast circle effect. Snipers are handy as well - especially for counter sniper work, as are the MMG sections, though less so.

Being an infantry-based army they do not like artillery. In a LC, your FOO and core arty will gain experience and become quick-response arty. Have plenty of mortars and 105mm or 25 pounder (smaller shells don't give them craters to hide in). Have ammo supply for your on-map arty. If you like the 60mm mortar - provide half-tracks to move these short ranged tubes up with the advance. Drop bricks on any annoying Japanese, suppress his on-map arty with some counter-battery fires etc. Any infantry advance of yours should be close (3-5 hexes say) behind a belt of fire that you advance a couple of hexes each turn - i.e. a rolling barrage.