I think CFB is best served if we maintain 4 fairly equal leagues after realignment. The SEC & B1G have the brands they need so my realignment focused on maintaining the w:

SEC: current league and add Miami & TCU. This bolsters the SEC's presence in the two largest states in the conference and the two with the largest amount of recruits. It also gives them a presence in two of the biggest hotbeds for recruits Miami and Dallas/Fort Worth area. TCU by themselves doesn't carry the region but with A&M it helps. Does Alabama, Auburn, LSU, Florida, Georgia and maybe someday Tn. again really want two more behemoths like OU & Tx or FSU & Clemson to have to go through to get to the college football playoffs? Or would they rather increase the embarrassment of riches they have recruiting wise for the existing schools by adding presence in Miami and Dallas/Fort Worth. Of course these schools can be good from time to time again as well.

The SEC has flexibility with this addition. They could either put Miami in the East and TCU in the west which would be natural geographically or They could move Auburn to the East which JR has lobbied for to some degree and send both Miami and TCU to the west with the iron bowl obviously being protected. OR both could head to the west and have Missouri and Auburn flip flop.

B1G: VA & Kansas or NC St.. If it is Va. & KS it is two nice adds for basketball and academics but don't overlook adding the state of Virginia for recruiting after already having Maryland/DC presence with Maryland. If NC St. was good enough academically the B1G may find it is better off in the long run adding NC St. to continue to build on the Atlantic state recruiting. The Its not any secret to PSU's recent rise. the B1G has helped them with adding regional partners and keeping them in the East with Michigan & OSU. The payoff to the B1G has been some huge ratings games involving PSU also. The league could try and revive Nebraska by creating these two divisions and giving PSU regional partners & Nebraska and other teams in the West the league needs to be strong some access to needed recruiting grounds and Iowa or :
1: OSU, Mich, MSU, Ind, Ill., Northwestern, Minn. Purdue

2. PSU, Neb, Ia., KS or NC St., Wisky, Northwestern, Maryland, Va., NJ
***If it is NC St. instead of Kansas, the league could possibly put Wisky in the first division for Minn., Indiana or Purdue because #2 is balanced enough competitive wise with NC St. instead of Ks.

ACC: ND, WVU, Cincy, UCONN
All the ACC really wants is ND, WVU gives the Northern part of the ACC interesting rivalries.
***An interesting play here is if the B1G goes with NC St. to try and lure KS. instead of Cincy but I think KS would rather stay with Big 12 schools and get the opportunity of playing UCLA & Az. If they were geographically close to the ACC I think they might.
PAC: UT, TT, OU, OSU, ISU & KS or KSU
If the B1G takes NC St. instead of KS. obviously KS is the choice over KSU.
6 teams gives the PAC CST content.