Good points. And I agree, need to look at realistic use patterns for the roster. Beilein is a coach who prefers a smaller rotation that other coaches --- usually a 7or 8 man core rotation, although in '17-18 I can see potential for a 9-man rotation.
Either way, IMO the baseline for the '17-18 squad is:
Simpson, MAAR with Poole & Brooks in the rotation
Wagner with either Teske or Davis as the backup
Robinson, Matthews on the wings with Wilson as the primary reserve (and maybe some small ball with MAAR/Poole on the court together)
Watson seems to be injury insurance/odd-man out in '17-18. One of Teske/Davis seems to be relegate to foul trouble emergency use. Any recruits for scholarship slots 12 & 13 will either be injury insurance/odd-man out OR will relegate one of the above to such role.
The goal, IMO, with the final two scholarship spots is for Beilein to find one more player to crack the rotation and boost the "on paper" look; most susceptible would appear to be Wilson, especially if an instant impact big wing is added.
But to me, the floor of the '17-18 group looks like a rotation that should be ranked in the 20s/others receiving votes range and earn a 6-7-8-9 seed in the NCAA Tourney. Upgrade the "Wilson" spot in the rotation --- either through recruiting or internal player development --- and the upside improves a line or two on the Tourney S-curve.