If the contract states that the service must be the same then yes, as civilian SAR crews are not trained in NVG ops and have less overland SAR experience. This is due to their tasking, not their ability, but is still a fact.
Even the Stornoway crews have a relatively small number of mountain jobs. You would not consider taking an ab-initio Wattisham crew to Lossiemouth, so the balance of experience must be a factor for consideration for SAR-H.