Uh, no...planes do have a maximum possible turn rate we call "instantaneous", which they cannot sustain. But they will also have a lower best rate of turn which they can sustain. And turn rate is a bigger factor in a nose-to-tail chase (of which, two fellows chasing each oter in a left Luftberry in an example) than turn radius.
Unless I am grossly misinformed (which actually is quite possible), "turn rate" cannot be two things at once. As you explained, yes, "turn rate" is instantaneous turn rate. To explain the
sustained turning ability of an aircraft, we call it "turn radius". Am I wrong? Again, I could be, I'm honestly asking.
Does not make sense to me that the term "turn rate" would be
instantaneous turn rate in one case, and then it would also be
sustained turn rate whenever it fits BnZs' argument.
Think about two fellows chasing each other in a Luftberry. What's more important...turn
rate and getting around for a "
one pull of the trigger" shot, or turn
radius and winning the nose over advantage for multiple pulls of the trigger? Again, I still believe that radius trumps rate in Luftberry. But perhaps I am wrong.