About P-39, P-40 and Wildcat I can just repeat only what I already sad, those were first line fighters during first half of war in Pacific. If you know about different (better) US fighter, pleas let us know, that will be something really new to know -not for me only.
Hurricane was sill used by British in Europe and Africa and I would not call it "second hand aircraft" in 1941.
As for Typhons, Moskitos and Spitfire9 ...that is already at last one and half year away from Pearl Harbor and more than 2 years away from Zero introduction and I am not going to debate it since I was speaking about 1940 and 1941.
As for "testing" Zero in China, I must disagree:
firsth combat flight in China:
on August 19 1940, 12 Zeros escorting bombers to Chunking
firsth battle:
on September 13 1940, 13 Zeros against 27 I-15 and I-16 over Chunking, all Chinese fighters shot down without loos of single Zero.
Until end of 1940 153 A6M were sent to China, destroying 59 Chinese aircrafts in air + 42 on ground without looses.
Before beginning of war in Pacific A6M made 70 combat flights in to Chinese territory with 529 aircrafths. 99 Chinese aircrafths were shot down with 2 Zeros lost to AA fire.
That doesn't look like "testing". Japanese started war in Pacific with only 400 Zeros. Mostly A6M2.
About Australian pilot I was little bit wrong so I must correct:
Book is ZERO FIGHTER by Martin Caidin, 1969 (I have translation not original)
It was Gregory Board flying Brewster Buffalo in 21th wing during defence of Singapore. He described hove British pilots in new Hurricanes (not Spitfires) which just arrived on cargo ships from England were all shot down when trying to fight Zeros in European style dogfight.
Later author (Caidin) write: "elite group of Spitfires with veteran pilots from Europe" was sent by British to Asia. In 2 battles 17 from 27 Spitfires were lost against only 2 Zeros. There is no place, time and Spitfire type specified but it was in 1942. He then quote Claire Chennault commenting whole thing as result of bad tactic of RAF pilots, trying to battle Zeros in a way they were used to fight in Europe …so I think it might have been somewhere in China.