re: If the SEC goes to the 3-6 scheduling option, which 3 permanent opponents should we face?

the heck with tradition. That was thrown out the window when Texas and Oklahoma became part of the SEC.
The permanent matchups going forward have to be regional for recruiting purposes.
Therefore, the only group that makes sense for LSU is A&M, Ole Miss or Miss State, and Arkansas.
The good teams will get there chance to play each other enough.