Tornado's are obsolete and are going to be replaced by the Typhoon which is supposed to be able to be Navalized with a very small cost. E3's are not carrier aircraft however E2D's are coming off the production line and are Carrier aircraft.
A Nimitz carrier Air Wing is made up of 80-85 aircraft of various types.
Create one Typhoon OCU, build all the Typhoons to Navy standard and that takes care of the Eurofighter fleet in one go with two carriers, with plenty of room for the Harriers, Merlins, SeaKings, Lynx's and Chinooks, E2D's.
You then have true interoperability between US and RN/RAF carriers and aircraft.
The one real obstacle to all this would be the "Turf Protection" by each service. The RAF will never accede to the RN having such airpower. The RN will never accept the RAF being the airpower for the RN. The British politicians would not accept going that "American" for national prestige reasons.
That and the fact the UK would not cough up the money.