This scenario is set in 1975; it deals with a British carrier group, heading home across the Atlantic at the outbreak of war, attacked by Soviet submarine and air forces. Total play time has been nearly two months, my goodness.
So that's my fantasy Royal Navy. Who's it going to fight? Practically anybody.
Carriers and submarines are dealt with. What about the rest of the Navy?
So Queen Elizabeth, Duke of Edinburgh and let's say Eagle are built during the early 1970s. That's the easy bit. What aircraft do they carry?
Many designers of fantasy fleets like to come up with all sorts of plausible-sounding technological developments. I'm mostly going to borrow ideas which historically worked for the Americans, and transfer them to the British with appropriate modifications.
I'll come back to what the British are up to, but the historical enemy has to be considered.
I often come up with alternate histories. The usual way of doing this is to change some historical detail and then speculate about what might have gone differently. In this case, I have a specific goal in mind, so I'm trying various divergences to try to get to the state I want.