During the exchange of views in the posts above, perhaps one needs to look at how things have progressed in the last 30 or so years.
Setting aside the strides made by the fair sex, we had people like Sir Charles Ness as a navigator and Sir Michael Alcock (Engineer) being AFB members. Currently and in addition to the principal engineer - Air Marshal Julian Young there is Richard Knighton who has just been made 3 star and is a major player in the central staffs.
CAS does 'sit at the table' by himself but in the background there is a large staff of specialist advisers who feed him the briefs etc. True, his operational experience and probably his personality as well are major factors but what he says, writes and does is a distillation of many contributions and the 'grooming system', which sees a large number of contenders at (possibly) gp capt level, gradually whittled down to a slack handful at 3/4 star level is the power behind the throne.
Old Duffer