Since Japan has so many planes I find MI are really useful as bullet sponges. The planes provide mobile killing power, the MI mobile protection for the planes and occupation.
If US decides to build up in HAW seazone, your aircraft are useless for a complete round (or more). Because you can’t fight that seazone (6 spaces). As US player I would just sit tight, build up and move to Japan via a northern route. Or go to Indies via southern route (Australia). Or build up TR with loads of cargo to take out Carolines. For every fighter it costs Japan it costs an inf for US.
And I think it will be a very dull way to play, or am I mistaken?