Yeah, but check the date on that report- 1943.. the A-H Tempest is an improved late-war series 2..
Rrrright. But if you look at, well, pretty much EVERY other aircraft, the trend seems to be increasingly larger turning circles throughout the series as sustained maneuverability becomes increasingly deemphasized. Were there exceptions? Almost certainly. But they're just that: exceptions.
Looking at the Spits, you have a pretty clear increase in turn radius from the I to V to IX to XIV. Even in the case of the Zeros (which are pretty much the definition of "maneuverability over power"), the development cycle was for more power, increased weight, and larger turning circles as the war progressed.