I always thought that the Lightning started off as a P1, a research vehicle. Because the cock-ups of the British aircraft industry and the Whithall that controlled it the RAF found itself without a supersonic fighter project. The Fairey FD2 would have been the best, the Bristol 188 the worst but Canberra production was going to tail off so the P1/Lightning was botched up to fill the slot.
Despite all this it still managed to have an illustrious career. The last of the sports cars.