The best use for the Wildcats would be with the FAA who no doubt would take as many as they could get their hands on.
And this is the reality of it.
no F4F Gladiator or Defiant could fill that roll.
(With salad or eggs? ) There was no way the RAF was going to equip with the F4F. None whatsoever and why would it need to? The hypothetical is that if it had them it would use them, not leave them on the ground, regardless of their weaknesses in performance. It's pretty obvious. As I have repeatedly pointed out, regardless of their performance, Fighter Command would be foolish to leave them on the ground. YOUR argument is silly in that if they had them they wouldn't use them. Dowding believed he didn't have enough squadrons - using Gladiators, Defiants, Blenheims was an option they couldn't ignore.
It's worth noting that the Curtiss Hawk 75, or Mohawk first arrived in Britain in July 1940. It took nearly a year before they were introduced into service with the SAAF after being shipped to Mombasa from Britain. Theoretically there was the possibility that they could have been used in action as they were ex French examples but were immediately issued to Maintenance Units to undergo fitting of British equipment (and a re-arrangement of the throttle assembly!), at which point they were kept in reserve.
The FAA needed Martlets and ordered them because of the lack of a modern single-seat fighter on its carrier decks. The Firebrand, which it was placing its single-seat fighter hopes was a couple of years away (or so it believed) and the Martlet and Sea Hurricane were stop-gaps, particularly since its efforts to get the Sea Spitfire pre-war bore no fruit.