It really is completely impossible to project, and I think K would say that if he were slipped truth serum. We've amassed a lot of talent, but it's hard to know how it will all fit together until we see how guys emerge over the off season and where our freshman are when they step-in on campus.
IMO, one key question will be whether Ingram can rebound and hold his own defensively at the 4 position, or will we have to use him nearly exclusively at the 3 -- with the move to the 4 being an occasional in-game adjustment against smaller teams? As much as K loves stretch 4s, it's a bit hard to see Ingram holding up against most of the 4s he will have to face in the ACC. If that's the case, that will necessarily push Amile into the starting lineup and squeeze either Matt or Grayson out of the starting lineup. And, on that point, I'm not sure why people seem to think Amile's going to be a minor player on next year's team. Under any scenario, I bet he averages a minimum of 20+ -- but more likely 25-30. I think he will be the undisputed on court leader for next year's team.
If Ingram is primarily limited to the 3, the other key question will be (i) how well does he score, and (ii) how well does he defend the perimeter. If he's a high-volume scorer (ala Rodney Hood or a poor-man's Jabari) and a poor perimeter defender, I think we'd probably start Matt to ensure we have a good wing defender to start the games. If Ingram's good, but not great offensively, but plays decent defense on the wing, I think Grayson probably starts to give us more of a scoring -- particularly b/c then we're playing with 2 bigs who are not going to be bigtime scorers.
With regard to Jeter, similarly, is he strong enough to defend the 5? If yes, I think he clearly has the most upside of the guys we have on the roster and may eventually work his way into a starting role. If he's struggling, though, I don't think his offense will be good enough to keep him on the court and he may find himself pretty buried on the depth chart behind guys like Plumlee / Obi -- who should be able to do a pretty good job defending / rebounding the position.
The Ingram / Jeter questions are just a couple of the many clear unknowns about next year's team. It really is impossible to know until we have a better sense of what guys like Ingram / Jeter can and cannot do on the court.