I think it would be a good idea.
Standardised aircraft and equipment, standardised training, central spare parts inventory, streamlined management.
The individual Air Ambulances can still keep their local identities for donations and fund raising.
The small regional air ambulances cannot hope to achieve any real efficiency. By merging in The Air Ambulance Service, commercial savings can be made (greater purchasing power) and the public will be more certain that they are getting value for money.