There is another one I missed, land based launchers for the RA, although I can't see a requirement for many/any, there is a long range/single ceil version of MLRS.
I think SSN provide a useful capability, able to move fast, and deliver a powerful accurate blow....the sniper! I don't think it should be its core role, we have limited numbers and our ability to project power is dependent on being safe from other subs, which should be the main focus. I think 10-15% stocks is right.
3(a), 3(b) & 4 are pretty much the same I guess, and should probably take the lions share, say 45-50%. I think 4 has real potential, particularly when the Tornado leave service, but I suspect the RAF regard it as a threat to fast jets, a bit like the RN and OPV/frigates!
2, I find the most interesting one, and much debated here; could surface ships take on much of the work of the fast jets, as their numbers decline. This could leave them to focus on the more tactic support work.
I can see a number of advantages: accessible to most areas, fast reaction time, able to maintain a continuous patrol/threat, cheaper to operate/maintain and able to carry heavy numbers. An issue raised before is the inability to reload at sea, I am not sure what impact this would have, (I don't know the process for reloading but must take the ship out?).
Since this was raise sometime back, I have wondered is VLS the only/best answer for launching cruise missiles. VLS have massive advantages for SAM: reaction time/never being compromised when reloading, but I would think these are of less importance to an offensive weapon. I am not suggesting a return to a huge missile priming approach, like the old Sea Slug, taking up the whole ship. More a palletized model, maybe even the ability to change warheads? Missiles could be fired from a ramp elevated up to 45% to aid perfomance?