Jimlad,
Of course your analysis of 'single-platform' capability has been the justification for the ramp-down in numbers over the past 20 years. The trouble is, that analysis only works if you can ensure that those platforms are in the right place at the right time. Setting aside operational-level considerations, such as whether a small number of "super-fighters" can maintain air supremacy without being able to sustain 24/7 operations, the strategic fact is that our leaders seem insitutionally incapable of keeping assets "in barracks", lest they be seen as irrelevant. And there is a requirement to have aircraft deployed for "Defence Diplomacy" purposes regardless of how capable each platform is; this gets progressively more painful the fewer aircraft you gave. You can sustain a 24-year detachment of Tornados to the Middle East with 7 then 5 squadrons, but if we are to have only one squadron of F-35s then it will have to spend at least 50% of its time at home, or it will soon not have any personnel - even the Navy couldn't retain people at that level of commitment over a specialist career.
So while I accept that modern aircraft are more capable on a platform-for-platform basis, basic consideration of our personnel will force us to scale back what we actually achieve with them. Assuming our 2* / 3* / 4* actually accept that, from time to time, none of the aircraft will be deployed on some operation or other as a way of justifying their existence. That might be a tall order.