Some fair assumptions, I don't know about ordinance load out between the Mustang and Corsair, however the USAF shipped 145 Mustangs over on U.S.S. Boxer as quick as they could to strengthen FEAF's assets in theater. That the Corsair was in use so long doesn't speak to me of Marine or Navy planning, USAF replaced Mustangs because of the MiG15 (Jet) threat, even the old P-80 stood a better chance than any piston engine warrior and the F-84 was being sent over ASAP.
As for the Corsair, I guess run what ya brung, if that's what's available, that's what you go to war with. Personally, for a piston engine attack aircraft the Skyraider has it all over the Corsair if you're flying in the Navy or Marines.
And my apologies re: loss numbers, I have no excuse as I was looking at the tome on my shelf and totally spaced on even getting it off the shelf.