Zinger is a good blocking TE, Dickson is a good receiving TE. Neither one is great at both, although Dickson could be if he continues to develop. Dickson & Zinger were going to be the starters this year, but with Crowton's offense there would be plenty of room for a freshman to contribute.
Miles said that Saturday's scrimmage was going to be most important for the second and third-team players with regards to the coaching staff discovering which of those players would be capable of contributing once the regular season begins. This may answer some of the questions I see concerning who played- as far as vets/younger players.
I just don't see the room for any of the freshmen...Zinger, Dickson, and Lott are the only ones I ever saw playing this year...maybe Cole.