At one point in the game thread, someone mentioned that TCUN still seemed to know what Ohio State was doing ahead of time. They may not have known the exact play called, but they certainly would be able to guess which play was coming next from observing the environment in which the play was called.
So, just because Stalions and Harbaugh were not on the sideline does not mean that TCUN cheating advantage was not still impactful.
1. Collecting the film data on Ohio State provided a rich database for statistical modeling. The signs and visual film evidence gave certainty about the play being called, the context in which it was called, the way the team lined up and then shifted before putting the ball into play, and the plays called sequentially before and after it.
2. This means that stealing signs provided more than stolen signs. The signs could be used as organizing variables to provide structure for some pretty sophisticated statistical modeling.
3. The key result would be that TCUN coaches and players learn a lot more about the likelihood of a certain play being called given an observed formation, shift, time in the game, down and yard context, etc.
So, you don't need Stalions or Harbaugh. The advantage is baked in.