For this entire tour, I have not flown anything but the f4u.
It's not the uber plane everyone cracks it up to be. I find it to be good at taking damage, good at dealing punishment with its 20mm cannons, and average to below-average at maneuvering and turning.
The situation you described doesn't sound at all implausible.
First, you have to know what your E was before the engagement started, and what the E was on the f4u. If he was at the top of his E curve and you at the bottom, that would make a difference.
Second, you have to know your engine temperature. If you had already burned up your WEP, and he had not used his at all but turned it on to fight you, that would make a difference.
Third, you would have to know his configuration and yours. If you were carrying droptanks and full ordinanace and 100% fuel, and he had nothing but a little bit of ammo and 25% fuel, that would make a difference.
Fourth, you would have to know who was using trim, who was not, who was using flaps, who was not, who was using combat-trim, who was not..basically, you would have to know who was a good pilot and who was not, or who was the better pilot.
There are a TON of variables in this game..thats what I am finding out in my month in the f4u. Basically, by flying this plane all month long, I have increased my skill as a f4u pilot tremendously. Last tour, I think I was lucky to get 1 kill per sortie max, and lots of sorties none at all.
This tour, its common for me to get 2 kills per sortie, and up to 4 or 5.
Hope that helps..other than that, don't know what to add.