I don't think you've been allowed to do this for several years. Back on NCAA 04, I remember I could do it. There were a couple versions after where you could play 12 when they still had 11 game seasons, but that's about it. They usually have just deleted the 1-AA opponents and played the 12 1-A games, but that didn't work last year when UNLV and Southern Cal played 13 1-A schools and it has a ripple effect that affects random teams far from the WAC. This is a must-fix and I really hope they have it figured out for this year, but I know not to get my hopes up with these people.