No need for minnie burner if you already have enough dry thrust!
Lightning F2 to F3: not really significant as the F3 was a bit heavier and grew into the F3a (or Mk6). Drivers of the F2a were happy with its performance, despite the older engine, better fire integrity and the good, yes good, endurance. Especially on one engine. Now that's enough thrust.
Shot one: What actually made the Bucc a decent jet was dumping the Gyron Juniors.....
As for the Jag: a better engine and a better wing would have made a difference, perhaps. Oh, and a radar and.......