Send volunteers to Nationalist Spain. Maybe send an attache as well. That will net you 20% of Franco's weekly army xp, plus whatever your volunteers manage to accumulate. That should give you enough xp to adjust your templates. Also, you may want to consider not doing the Marco Polo Bridge focus. That focus lets you go to war with China, but it inflicts a huge malus on your army that you have to buy off in stages. Buying the malus off makes the USA more powerful, but leaving it there makes your army fight at around 50% strength (which is suicidal). In the latest versions, you can't declare war on China directly without WT being around 75%, but there is an alternative: wait for China to provoke war.
Communist China has a national focus that lets them sabotage Japanese infrastructure and factories in Korea. When they do that, Japan gets an event that lets them declare war on both Communist China and the Republic of China. Declaring war with this event does not inflict the Marco Polo Bridge maluses on your army, but it is very likely China will still be suffering under its own army malus, which makes them fight at around 50% strength.
This means your army will be at 100% effectiveness, while China is at 50% effectiveness, essentially making your army twice as powerful than their army without you having to do anything. You won't need 14/4 anything to push them then. Plain old 7/2 will do.
Also: consider using light tank divisions. China doesn't put anti-tank guns into their divisions until very, very late in the game (if they somehow survive that long). Light tanks are resource-cheap and can shred infantry very well. Give them support engineers and they won't be penalized by bad terrain as much. As Japan, you will find that light tanks will go farther for you than for most any other nation (everybody in Europe has AT support by 1939, most people in Asia don't have it till 1944).
If you want to go pro-gamer, you can declare an early war on the Dutch East Indies right out of the gate. Join the Axis, justify on DEI, get docking rights in Italy and Nationalist Spain, move your fleet to Germany (search for "Sunrise Invasion" on youtube for a how-to video about this... there's a trick to moving the fleet you'll need to see), put a stack of infantry in Germany and plan a naval invasion into the Netherlands (the middle port; AI rarely guards that in the early game). When the justification is ready, invade the Netherlands and capitulate them (don't call Germany in). Then puppet the DEI for manpower (or annex them for resources) annex Curacao for oil (and a staging ground for an invasion of the USA) Guyana for aluminum, and then do whatever you want with the Netherlands. Puppet them, annex them, leave them independent; doesn't matter. Just leave the Axis immediately afterwards. This gets you a lot of rubber, oil, and aluminum which you'll need for the war in China. If you shower a puppet DEI with lend-lease guns you can get an impressive puppet army from them, or you can create colonial divisions with their manpower. Or use their manpower for garrisons in China. Having the DEI in your hands gives you a lot of options for later in the game.
