BEages, you are correct however the case I relate was an E and it was the first time they had been doing PIs with a manoeuverable target like the Vulcan. The problem with mutuals means you learn how to kill your buddy but have no idea how to handle a dissimilar type hence the development of aggressors and Top Gun.
The Mig 21 was half the size of the F4, had a fraction of the range, minimal kill shots and poor visiblity, but that did not make it an easy kill.
Digrssing from the F4 v to another tale of Lightning v F16.
The Lightning driver related how pleased he was with the F6 performance against the F16 in a burning and turning furball with the pair almost equally matched. Then the F16 used his burned and waxed him.