Air Ambulances would have to go from having a pilot and two paramedics to a SAR trained pilot...
The scenarios being mooted on this and other threads regarding the type of winching would not necessitate the pilot being SAR trained.
The pilot would need to have completed an approved winching course and the recurrent training. If the Air Ambulances in the UK want to winch because they believe it will give them an increase capability and they have completed their own feasibility study and on-going risk assessments then why not? The SAR Pilots course whilst necessarily comprehensive would be unnecessary in length and content for the limited day onshore winching that the Air Ambulances are considering, which would be more than covered by a CAA approved tailored course.
This subject is quite an emotive one with some who would deride the possibility of other agencies expanding into "their" area, personally as this will save lives I'm in the "For" camp.