So a scheme like an abridged version of the Mil Landing Point Commander course for Station Officers and the like would be a bad idea?
Certainly not. Any further training is obviously a benefit. I would be very interested in talking with an officer on scene to obtain as much information as possible to locate a suitable landing site. Wires are always more visible from the ground and if there is a qualified person there to assess a HLS then so much the better. I just don't see where marshalling a helicopter would be of much use.
So, let someone else who isn't pre-occupied with their primary tasks concentrate on it.
I must have flown to hundreds of accidents in my 15 years as a HEMS pilot and don't think I can remember any where Police, Ambulance or Fire and Rescue Officers were standing around doing nothing. In fact at many of the scenes even I ended up either directing traffic, holding infusion drips, comforting relatives or carrying stretchers.