So, I've been thinking about it for a couple days, and what I think the Royal Navy needs to do is to step back and conduct a thorough evaluation of their carrier fleet before making any decisions. Take the time and do it right. And they need to realize that their existing carrier fleet is totally unsuitable for modernization.
This is strictly my opinion, but I think the British fell into the trap of hyper specializing their carrier fleet for the war they fought in WWII with little to no thought of what would happen after. Their carrier designs were focused on fighting the Germans in the North Sea and the Italians in the Med with little to no consideration of operations in other theaters. Somewhere along the way, the UK lost sight of what the primary purpose of an aircraft carrier was (to deliver air power from the sea) and became mission fixated on keeping the Germans out of the Atlantic and the Italians bottled up in the Med. Now, weather they realize that by 1948, I don't know. I think in some ways, they stayed mission fixated and simply swapped "Soviets" for "Germans and Italians."
What I would do? Pause construction of Eagle and Ark Royal to give you time to design and build them to a common standard. Do the same with the Centaur class. Pause them while you work out a common design standard that can maximize those ships. I also plan on only completing 3 of the class and offer to complete the fourth for whoever is willing to pay for it. This gives you five brand new carriers in service within 10 years.
Despite what I said earlier, you do need to modernize the existing carriers a bit to cover the gap until the new ships are online. But what you don't do is break the bank doing it. Pick and choose which ships you want to keep until the new ones are ready, and give them the bare minimum needed to keep them viable for the next 5-10 years. That means no major hull surgery or alterations. At most, they get hydraulic or early steam cats, new arrester gear and maybe an angled deck (despite the way it looks, adding an angled deck is actually a cheap and easy upgrade that can be done in under 6 months).
