This would be
12-0 BYU losing to 11-1 Kansas State in the CCG
And Iowa State being 11-1 with their only loss to Kansas State
That's the only scenario I see where the Big12 has 3 teams considered. A 2 loss Big12 team would likely not be top 12 end of the season unless the other conferences just beat each other up and have only 3 loss teams