If a 'safety pilot' is really required on an SPA BE200 why not operate the aircraft 'multi-crew' and be done with it?
Because the 200 is a SPA so a second pilot is purely supernumerary and unable to log time. I doubt you are going to get someone to sign up to a job that they can't log time on.
Personally I don't see what the issue of someone wanting to fly an SPA taking along a safety pilot for comfort, company or whatever. If they are acting as a safety pilot then you would assume they can or would want to be able to actually fly the thing so would want to be rated.