Geography has been a huge factor in the SEC's success. So has tradition. Almost everybody has a long history with everybody else. But Texas isn't that far away, and it's not exactly a stranger. The Aggies and Longhorns are former SWC rivals with Arkansas.
Twelve seems to be the magic number for conferences.
It splits neatly into two six-team divisions. Having checked my Rand-McNally, I concur. Vanderbilt, we need to talk. Ole Miss and Mississippi State, please wait outside. Ole Miss and Mississippi State would join Tennessee, Florida, Georgia, South Carolina and Kentucky in the SEC East.