I did not recall that the IJN CVs were understrength. There's a great book on the air war in the Pacific, "Fire In the Sky". Don't recall the author, but it does a great job of describing the strengths/weaknesses of both the US and Japan regarding the air war. It addressed all aspects, such as equipment, training, doctrine, logistics, and the asymmetric weapons development cycles of both nations, and how all this pretty much per-ordained Japan's eventual defeat. I believe the same author also did one on the naval war, but I don't have that one (yet).