I would suggest cutting the number of RAF fast jets is a short sighted move, particularly as GR4 works, is paid for and will be useful for a decade or more. UK PLC needs as many assets as possible, and be they RAF/FAA or joint, we just need to keep the numbers up before short sighted politicians drive them down, when it's gone it's gone.
We are only getting two carriers (we hope), there will only be one available at any particular time and a carrier can only be worked on a mission for so long before the crew and ship need to be relieved. Many of the missions the UK has been involved in would be unsuitable to a carrier force of one ship.
Would you want a carrier to be policing a no fly zone for month after month after month? Being in theatre for 6 months before the shooting starts as in the build up to GW1? Having 2,500 crew on half a dozen ships burning fuel to police a no-fly zone is not economical when the RAF could do it with a tent city, 20 Typhoon/Tornado and a couple of tankers.
It shouldn't be pro or anti RAF/RN,some missions can be carried out with HNS, the RN will never have the ships to be the sole custodian of the UK's offensive punch.
Our economy should be able to support a fast jet fleet of 100 Typhoon and 100 Tornado now and still pay for the carriers, looking to have a future fast jet force of 100 Typhoon, 100 F35 and 50 or so UCAV platforms, with at least 2 squadrons of F35 on one of the carriers for the UK big stick to administer a short sharp kicking if required.
In reality with 100 of each type, we would be deploying 18 of each maximum for a deployment of moderate length, that is similar to the libyan deployment with supporting types, we could not deploy in those numbers if we only had two tiny fleets of F35/F18.
Seeing as the French Navy will be a similar size to ours, it may be telling that the 2008 french white paper set the air combat fleet at 300, 240 for the airforce, 60 for the navy, a front line strength for the AdA of 158 Mirage 2000 and 59 Rafales according to wiki. I would suggest the French anticipate a similar mission profile to us, and the numbers of Tornado and Typhoon likely compares so it might be unwise to drop below that level?