That has more to do with a 16 team conference sending 6 teams to the postseason, actually. And, there's no restriction on how many wildcard teams a division can send. With two spots, one division could (and has) fill both spots. I remember a season where the Colts won their division, and the Titans and Jaguars were the wildcard teams. There are 120 FBS schools, and only 10 spots in BCS games. Plus, once your conference has sent two teams, the rest of the teams in your conference are all excluded, even if there are available "at-large" spots still unfilled.