Beags wrote ''Why is there such an utter obsession with minimum different aircraft types across the services these days? Does a GR4 replacement really need to be carrier-capable? Or a fleet defence interceptor really need to be 'day one' stealthy?''.
the obvious answer is £££££££££££££££££££££££££££££££££££, but another is flexibilty.
lets say we had, as you suggest, an RN CVF with F/A-18F, and the RAF went with Typhoon, GR4, and then further down the road swapped GR4 for CF-35A. if we subsequently faced an adversary, or series of adversaries, against which land-based airpower was the answer, then the RN's F/A-18's could join the party in a surge capability. if however we found ourselves engaging in a series of conflicts in which carrier based aviation was the only way to engage the enemy, then the RN's F/A-18's are quickly going to get shagged out, with the RAF's great pool of hugely capable fast jets unable to assist.
the real answer is a single type fast-jet fleet that can undertake all the fast jet roles. F-35C can do land and carrier based strike and AD, as can F/A-18F. Typhoon, even at T3, is much more of a one trick pony.
i wouldn't be remotely surprised if its one of the reasons the Indians went for Rafale over Typhoon. being carrier capable may not have been part of the requirement, but having a carrier capable multi-role aircraft in the back pocket gives them options in the future - an aircraft that's tied to one basing type does not give you the same options...