Surely we need to see a small uplift coming out of SDSR given world events and what their airships are saying about FJ numbers - eg enough T1s retained to stand up a sixth Typhoon sqn (20-25 airframes?) - unusually there's a relatively good value and achievable route available to alleviate a bit of pressure.
Alongside that some sort of modest uplift too in earlyish F35 acquisition - enough at least for a third (and ideally fourth) front line sqn, at which point the T1s could go. A nudge towards a force that you can do something relatively sustainable with, and a better fit too (presentationally and actually) with operating two carriers. Nine FJ sqns doesn't sound especially lavish to me and ought to be a realistic outcome.