The media makes the conference; pure and simple. Remember way back when only the Big 10 seemed to matter? The SEC was hardly on the radar with most considering it a 2 team conference; Bama and UGA/TN. Everybody else was an also-ran. Now granted, the level of play across the board has improved in the SEC, but it is only within the last decade that they became "THE" conference, and most of that is media hype.
The ACC was a joke until they raided the top teams from the Big East.
Nebraska and Oklahoma once dominated CFB; their match up was the game of the year along with Michigan and tOSU. And one of these games more often than not lead to an NC! Occasionally a PAC team would pop up; but only USC or UCLA as the rest were also-rans as well.
Now I'm talking way back here, most of you on this board won't remember some of this, but the nature of CFB is cyclical and teams are up and down. Look at ND this year as an example.
Bottom line is there will be a time when multiple Big Xii teams will be at the top of the CFB rankings early in the season until they start to knock each other off; which is the good and the bad of round-robin play. The other larger conferences can dodge some of the other teams, but you can't in the Big Xii given the current make-up.