I'd say Grant is closer to 6'7" or 6'8", and Dortch looks to be closer to 6'10" (he appears taller than Bailey).
Dortch is the skinniest guy on the team, and cannot play the 5. Grant has apparently shown some skills with rebounding and defense in practice, but does anyone REALLY think if he showed better than Martini, Sommerville or Ogbole ... or Hayes, that Pikiell would NOT play him? Obviously a decision has been made to date that Grant is not ready (he did get a couple of minutes versus Wagner - and got a couple of rebounds and missed 2 3-pointers from the corner).
You just cannot play 11 or 12 in the rotation - even 10 is a stretch. Who would Grant play ahead of? I could see a scenario where Grant gets a few minutes: A frontcourt injury, or really severe foul trouble (would you burn his redshirt for a single game foul trouble issue?).