Welsh1, I have a very similar background to you, and have equally struggled to understand the approach the RN is taking. You cannot blame politics and poor financial management for everything. The SDSR just showed a complete lack of strategy.
Everyone tends to frown on fantasy fleets as think that it is just amateurs playing games. But, what they do help with is explain thought on the balance of the fleet, which in my view is completely out of kilter.
I think that the days of a separate ARG / carrier strike groups are long gone. As such the we should end up with two groups (one active and in reserve), being sized up and down as required. Each group would consist of the following:
1 x CVF
1 x LPD
3 x T45
3 x T26 ASW
1 x SSGN
2 x Fleet tankers / AORs
This would be our big stick in the world.
Additionally, I would have a T26 ASW on station as APT(N) - requiring three vessels in total to be rotated.
'Global presence' would formed into 6 'squadrons', 3 active at each time, each consisting:
1 x JSS (capable of carrying a RM company)
2 x C3
3 of the squadrons would have an extended T45 (better ASW, Harpoon plus TLAM). Also on top of this would be the 7 astutes and a further 4 SSGNs for nuclear deterrence.
In addition to this I would have a costal command which would be responsible for the defence of the UK and all dependecies, including Gibraltar, Falklands and Caribbean:
12 x C3
1 x Ice patrol
3 x JSS
18 x Inshore Patrol
MCMV and survey capabilities would be modularised, and capable of being deployed on a C3 or anything larger, including the JSS.
This would give a balanced fleet, in terms of number of vessels its very close to the SDSR. It explains why I think the C3 should be more than just a new River Class and why the T26 should be basically a like for like replacement for the T23 (without the TLAM and other bells and whistles). This would leave the requirement for more AA support, hence a beefed up second T45 batch.