Part of what makes the Big 12 so tough is how much of a copycat league it is. You can stay ahead with your tactics only so long as other teams lack the personnel to mimic it. Oklahoma’s advantages from their “21 spread” sets are virtually dried up now as we saw multiple teams copy their utilization of the flex TE.
This is going to be the thing now, with defenses spread out now you need to find matchups and no one creates those better than a flex TE in the middle of the field. Read up over at Football Study Hall.