Hi redatlanta, as he isn't motivated by the normal things like money is there any way of motivating him with grandiose praise? Probably not, and I agree with you that your RAH won't be able to talk him around either.
The harm minimisation you are practising now, plus looking urgently for a talented replacement seems the only way to go. Maybe try for a driven young person who wants to go out on their own but can't afford their own place.