I haven't played with the carriers yet.
But inspect the tech tree aircraft:
the Japanese get more aircraft squadrons,
but the US squadrons do more damage.
Example: tier 10
US dive bombers max dmg: 7500.
Torps: 9867
fighters: 120.
All 2150+ HP.
Japanese:
Dive bomb: 4600
Torp: 8567
Fighter: 148, but below 2000 HP.
Those are max dmg numbers; it is possible the Japanese torps have less penetration/cause less flooding etc also.
Another point: hangar capacity: tier 10 US: 136.
Tier 10 Japan: 100.
I believe this means the US one has 36 extra spaces for "spare aircraft" in case part of a squadron is shot down.
This deserves to be accounted for, as it is quite likely that you will lose parts of a squad etc.
