If I were looking at this, I would guess we carry 3 TE's and I might prioritize them this way:
1. Mike Gesicki as the starting move TE
2. Dwayne Allen as the starting inline TE, and veteran leader to the young TE group
3. Marqueis Gray as the combo TE/H-Back/FB who gets a lot of time from all three positions with most of it being some form of run blocking.
4. Smythe as the reserve blocking TE
5. O'Leary is probably on the outside looking in but will compete with Gray for the combo role and probably lose because he isn't effective enough as a lead blocking FB.
6. Derby is probably going to the practice squad if he is still eligible. Longshot to make the roster, but he will be given a shot.