HAL,
The points you make are interesting - it does seem that, under current plans, the MOD will have to spend a lot of money on SAR-H for very little return.
There is, of course, a much cheaper and feasible alternative to SAR-H, which has the added benefit of delivering exactly the same level of service which the UK currently enjoys, but apparently this plan has been blown out of the water because it would upset the consortia which are currently rubbing their hands in glee at the prospect of being given vast sums of money to provide a potentially inferior service...