Duke has room for both Sexton and Green, especially if they can be convinced Frank Jackson is one and done (not unrealistic) or if they can be convinced K will play small (likely).
PG Collin Sexton (24 min), Quade Green (16)
SG Frank Jackson (32), Gary Trent (8)
SF Kevin Knox (8), Luke Kennard (32)
PF Mohamed Bamba (16), Knox (24)
C Wendell Carter (28), Bamba (12)
DNP - Chase Jeter, Javin DeLaurier, Deng Gak, Antonio Vrankovic, Sean Obi
The following season, Green would start and get huge minutes, with Kennard as the only other good PG option (I assume both Sexton and Jackson will be gone). Really, we need two point guards in this class, especially if one of them (Sexton) is a clear one and done.