Careful use of blockers can buy you a round or two. Sometimes they can be used to help your fleet escape if you don’t want it to die in sz6. After it’s escape it can round India, convoy raiding the Middleeast, and then support the Italian fleet. Just an option.
Since the problem you seem to be having is Russia, I think you need to rethink your mainland strategy. What do you hope to gain in China. Can you gain those same objectives with a holding force instead of an attacking force? Is China really a threat to japan since it’s troops can’t leave china?
Now those Russian inf. How much of a threat are they compared to Chinese? Can they take Korea? Can they retreat to moscow to fight the Germans? Both of these are things the chinese can’t do, I don’t see any reason to fight the Chinese. Use that army in China to attack your real enemy, the Russians. You know, the enemy that Germ and Italy are also gunning for. Not China.
Of course if you like your strategy, then stick to it. I try to follow the advice of ‘The Princess Bride’, don’t get involved in a land war in Asia!