Not as hard as landing on Battlefield 1942 carriers... especially when they're turning and moving.
(Unless you do that weird glitchy 180° turn to drop airspeed to zero and make your plane land like a jumpjet. Even works on mountain peaks, but you're not going to fly it off later.)
At least Shoukaku was easier to land on. And the Duckies didn't have AA, so...
I'm thinking more the fly-by rearming that never actually touched the carrier. Coupled with the occasionally newbie pilot trying the same thing and taking out the bridge or whatever helicopter happened to be lifting at the wrong time.