What makes bishops 'ontologically different' is the laying-on-of-hands of other bishops, successors to the apostles and sacramental agents of the institutional church.  It's somewhat akin to transubstantiation in the context of 'sacred personnel' -- their humanity is but an 'accident,' according to scholastic philosophy,  the 'substance' is the bishops' reconfiguration as 'alter Christus'  through the mandate of the Holy See and the authorized ministry of other bishops.  Their mommies need to set them and the CDF straight on family matters' and reality in general!