Beats me too! The point about "hedge-schoolmasters" is that many Irish songs (both in Irish and English) are laden down with classical references. One theory is that this evolved from the work of itinerant teachers who, with a modicum (nice word that!) of Latin and Greek, taught people outside such mainstream education as then existed. That said, I've no idea whether Claudy Banks is basically English or Irish (lots of rivers of that name).