A lot of times opinion/s tend to swing in pendulums.
And a lot of time people confuse cause and effect.
And a lot of times histories are written by people that don't want to place the blame on living high ranking politicians or Military staff (or piss off influential relatives of dead ones).
The British did a lot of things right and they did a lot of things wrong. So did everybody else. Plenty of room to pick and choose examples for arguments.
Poor training and bad tactics are very hard to pinpoint compared to top speed or turn or climb. Poor specifications (equipment fit) is harder. But poor training (and the officers responsible) are a lot harder to identify. Poor training can negate any advantage in firepower.
We can ague for months about if the Japanese Navy had better pilots than the US navy in 1942. But there is little doubt that some of the US pilots were very good. Which is why the USN managed to survive using F4Fs so well. Good flying, good gunnery and good tactics made up for deficiencies in aircraft performance.
O'Hare's performance was a classic, but extreme example. Two other Wildcats were lost the same day trying to use stern chase zero defection shots against Japanese bombers. Attacking slowly (trying to overtake the Betty bombers) into the best defensive gun on the Betty (the tail 20mm gun) gave the Japanese their best chance. Not good tactics. O'Hare's diving defection shooting from the side made return fire difficult (single 7.7mg fighting the slipstream) and gave him a bigger target. From an aircraft standpoint, the F4F-3s large ammunition capacity allowed for 4 attack runs and putting bullets into 7 (?) aircraft.
For some reason, in some military forces, many leaders thought their service men were not able to do certain tasks. The British spent a lot of time, money, effort trying to get around teaching air to air gunnery. Teaching air to air gunnery takes time, effort, fuel/ammo maintenance costs.
Where to place the blame for operational results (or lack of) gets difficult.
Agree with all that, and I'd also note, it looks pretty clear that US Navy dive-bomber training was top notch as well, which becomes obvious when you compare the operational outcomes of SBD flown by US Navy dive bomber or scout squadrons, vs SBD flown by USMC squadrons, vs. A-24 (USAAF version of SBD) flown by US Army pilots and by various Allies. It's really night and day, both in terms of mission survival rates and ships hit and sunk.
It's possible that is the main difference between US P-39 pilots and Soviet. The Soviet pilots seem to have gotten a lot of training on type, at least initially.
You can do similar with the Wildcat. British FAA pilots seem to have done fairly well with the type, outcomes are generally good (I don't know the entire operational history of the Martlet / Wildcat in FAA service but outcomes seem positive in the cases I'm aware of, including against land based fighters like Bf 109)
As for the tail-end pursuit, I think there is a shakeout phase even when the training and tactics are good. AVG made several mistakes like that in their first couple of engagements, and lost some guys, but word got around pretty quickly. I think USN pilots shifted into 'best practices' pretty swiftly overall, but there will always be exceptions in the stress of combat.
Similarly, you can see British and Commonwealth pilots flying both Hurricanes and Tomahawks or Kittyhawks in North Africa, under the same higher leadership and the same training regimens. In some cases this is clearly augmented by quasi-insubordinate insistence by certain Commonwealth pilots on instituting reforms (Clive Caldwell establishing 'shadow shooting' as field expedient gunnery training, and various Australian pilots personally testing his Kittyhawk on higher than regulation bomb loads to prove fighter-bomber viability).
But from the outset, you can see that P-40s had better outcomes, in terms of friendly losses and (especially) enemy losses than the Hurricanes in North Africa.
Just as you can see US units flying P-40s in the Solomons and New Guinea, doing much better, as in twice or three times as well, as P-39 units from the same air force flying out of the same airfields. And at least a few of the P-38 pilots pulling way ahead of everyone else.
Or British pilots in Burma and India flying Hurricanes, right next to their peers flying Mohawks - admittedly a very small sample but they seemed less likely to get shot down.
