Tarnished, I beg to differ in the detail: The winning ingredient will always be the aircraft that can pull the highest g at the lowest speed and sustain it.
Rate of turn is (g Tan Phi)/speed, thus and as you state, with two different aircraft types, but with identical g limits, the type that can sustain the g limit at the lowest speed will have the advantage of the higher turn rate.
However, a sustained 7 g aircraft at 520 TAS generates a RofT of 15 deg/sec, but this is equivalent to a sustained 6 g aircraft at 410 TAS, or 4 g at 270 TAS. Thus, the critical factors are those that enable an aircraft to sustain g - the aerodynamics and thrust and not necessarily the highest g.
So we need a sustained 4 g capable SE5a! More thrust, less drag.
Where the objective is to bring a weapon to bear on the target (notwithstanding a fixed bore-sight or an off-axis / HMS), then the rate of turn is the dominant feature. For the extreme and unrepresentative case; the helicopter has a high rate of turn and could align a weapon very quickly; however, a more practical issue would be the rules of engagement, then politics as discussed previously, will be the deciding factor.
Anyway, wasnt the last war that required a turning fight circa 1976?