You don't need 7 odd SH squadrons to provide very occasional military assistance to civil authorities!
No you don't. But you do need 7 odd SH sqns to provide simultaneous 2 Coy lift, framework tasking, support to contingency and ABTF, SF support, UK national tasking, training and ops workup and cabs in maintenance.
I'm out of the HQ environment now, so unsighted, but what happened to the notion that the Merlins would go to CHF and the Merlin Force was to be backfilled with 14x CH-47?