It's pretty easy for the D coordinator to set his defense one way, then switch it after the prairie dogs go back in their hole. By that time, there is no time for the offense to counter. They are stuck with the play that is called.
The QB has to able to recognize the defense and adjust without looking to the bench. Ideally, they should be calling two plays in the huddle and the QB selects the one to run at the line of scrimmage after looking over the D.