The Unions at Comair and Mesaba should probable try and get together and force the flying to be 'single-carrier' by the NMB. Both pilot groups have some very old and some fairly new pilots and it could help with effiencies to cut out an entire layer of management(hopefully the worst ones) and allow more opportunites for the guys on the CRJ equipment.
I left out Compass because they fly very different equipment and also they have a unique structure with the flow up/down with DAL (also they are represented through the DAL MEC).