The House Ruler and Consort are already occupied by NPCs, and the 3 PCs we have are the House Swordmaster, Warmaster, and an Heir/Envoy.  The 3 roles that would immediately come to mind for your spy idea, Beorning, would be the House Spymaster (duh), a House Advisor (who is not entirely what he seems), or the House Marshal (who better to enforce the law than someone who knows how to work it).