Gentailmen not only was the Frank considered the best Japanese fighter of the war, it also held it's own aganst all late war US planes. When they were fist deployed operationaly in China they gained local airsupiority over P51's in their area:
Capt. Wakamatsu changed his mount to the ki-84 and in his first combat sortie in the new fighter downed two P51's over Wuchow. He went on to kill at least 7 more P51B/C's before he was caught landing his damage plane by a low leval flight of 10 P51's who shot him down,
That gentailmen is the fate of the Japanese Airforces in WW2, they lost do to attration, not because their planes sucked.
During the initial stages of the war the Zero was a far better fighter than the Allied planes at hand, not untill the Coursar and the P38 shoed up did things change in that regard, then later in the war as new Japanese fighters showed up like the George and the Ki 84 were US planese realy chalanged, but it was a war of atration and Japan was doomed. Their are numiours referances to one flight of a certain plane type waxing another type, going both ways, these arguments are not realy good for determing how "good" a plane was, The Frank is every bit the equil if not better in some ways to the Hellcat that is a well established fact, and frankely i was kinda suprised to hear you arguing it the other way:) Not to mentio other plane type's like the Ki 100, the Ki 61 and the Jack, all of which held their own for a time and in some cases even up to the end:
"Two Japanese types that proved to be anything but cannon foder for USAAF fighters were the Ki 84 Hayate, and the Ki 100. With skilled piolets at the controlls both aircraft could more than hold their own aganst the Hellcat, Coursare or Mustang."
Both pasages taken from Japanese Army Air Force Aces 1937-45
By Henery Sakaida
