I'll give you that the F4U could certainly handle the Mustang and Jug at low level, but not so easily higher up. Plus the P-63C/D could best them all at low-to medium altitude performance, and still competitive higher up too. And had the firepower to take down the Jug easily (within 300m) with the 37mm M10 (or possibly the far more powerful, but heavy M9 of the P-63D) while the .50 cals of the P-51 and F4U, or even the 20mm's of some F4Us (which many lacked gun-heaters for high-alt) could be absorbed by the Jug in considerable amounts.
Though the P-47M (or N with half fuel load/no wing fuel= 1000 mi range) at altitude would best them all, and even be a challenge down low.
Though the Tempest Mk II would also be quite a contender.
Don't even mention the P-47J or P-72...
If the British hadn't spurred the US jet program (in Gen. H. Arnold) in 1941 (which had already been working in Lockheed in '39 and with NACA contracts in '40, but had taken low priority) The US would have still had a 500+ mph (estimated 550 mph theoretical with contra props and 3,000 hp) fighter in the P-72 and possibly even faster with an uprated later model Wasp major (3,500-4,000 hp, possibly meetin the original theoretical 550mph). This could have been in service by early 1945 and would be devastating to early jets, and would be easy to convert to, and far more reliable and fuel-efficient. With the P-47N's wings it would have made a good escort too. And despite the (relatively) high drag from the thick wings, the standard P-47 had a mach limit of ~.75+ and the P-72 with improvements and dive-flsps of late-model P-47N's should have been around .79 mach (similar to early jets: Meteor I-III, Vampire I, Airacomet, He-280)