I have and read Samuel Miller’s The Ruling Elder some years ago, but without then much in the way of critical faculties operative.  Perhaps I need to read it again.  I, too, think I’d prefer Clark’s logic on many things.  Are we sure we do not have a remnant of priestcraft in the matter of the administration of the sacraments?  If, as example, 40 reformed Christian laymen and women found themselves irrevocably isolated on a deserted island, they could and should form a church, which would include elders and deacons.  Hopefully, they would have the Bible, the Institutes and the Confession/Catechism with them, along with Greek and Hebrew texts of Scripture.  We set apart officers based on the doctrine of calling, as verified in observation of gifts and Christian life, with education as a necessary but not sufficient requirement.  We do not hold to a literal apostolic continuity imparted by the laying on of hands of other elders, as there would be none in this hypothetical situation.  In a sense, the congregation, the community of the professing saints, would only be recognizing the calling, life, and gifts, not imparting them.  I believe that elders and deacons should not be selected or elected as much as recognized, similar to the way in which the canon of Scripture was determined.  Election is the formal outworking of the collective, subjective recognition.