SPARTANBURG, S.C. — The Southern Conference has always been a league of football powerhouses. There’s always been a Big Three, and two of them have been Georgia Southern and Appalachian State since the mid-1990s. Wednesday at the SoCon’s media day at the Spartanburg Marriott, most of the talk surrounded GSU and ASU and their departure from the SoCon to the Football Bowl Subdivision Sun Belt Conference.