A Brewster Buffalo shoots down an LA5 over Finland.
Doesn't mean the Buffalo was "able to compete even with the best the Soviets had to offer" -- just means it was able to get a kill due to the circumstances surrounding that engagement.
In no way, shape, form, or stretch of the imagination is the Brewster comparable to the LA5, but it can still kill them.
The fact that the Ki100 (which was NO BETTER, got that, NO BETTER than the Ki61) could get a kill under certain circumstances, does NOT mean it was better than the US planes it fought.
Nor was it faster at any alt. It could only turn tighter circles. Well, against the US fighters, a tight turning radius wasn't going to seal the deal. A6m2s, A5ms, Ki43s, etc *ALL* had tighter turning circles than any of the allied planes that shot them down in record numbers.
It borders on the edge of propaganda to say the Ki-100 was in any way competitive with the late-war US planes. It was a 1942 plane, with an even older engine tacked on in 1944 because they lost their inline engines production lines. A stop-gap, a last-ditch effort. It was not superior, it was not "great" -- I'm rather P.O.ed about the propaganda the Ki-100 receives. Most of it is out and out fabrication, the rest gross exaggeration, and some of it just plain LIES (no, they did NOT shoot down 16 hellcats on their first mission).
(*steps off soapbox*)