Duncan,
I think the past 10 years showed that sticking to old assumptions, mission profiles and capabilities, as the RAF and MLD did for their fixed wing aircraft, proved the wrong idea. We should learn from our mistakes.
I think the RAF has to open up, start with a blank sheet of paper and draw up & check the requirements for the next 40 years. And they probably don't look like the past 40 years.
Flexibility is the answer in a global environment that proves unstable, ask our ally, Tu-16 pilot Mubarak who had it all sorted out.