Earlier this season I was focused on finding a nice 4/5 guy, but this draft is pretty deep in the 1/2 area, and that is a more important role in today's NBA. Given Kemba's recent health concerns, we should assume that we won't be getting more than another 1 or 2 years of top service from him at the point guard position.
I don't like the idea of drafting to fill a need and I'm not sure of your Kemba assessment but I do think DA will end up in a position to draft a high ceiling PG in this draft.
Point guard is a position that I think its best to either draft really early high ceiling players or wait till late in the draft. Waters is a prime example of a player drafted late who appears to be a serviceable backup PG. Later (2nd round) in this draft I think Payton Prichard and maybe Cassius Winston will be available and both will be playable NBA point guards.
The Cs at #17 are in an interesting spot because PG/Combo guard is the strength of this class.
All of the players listed above are guards who COULD go before #17, the chances that all 8 go seems slim to me. Out of that list Mannion may have the highest floor but also the lowest ceiling. I could see DA targeting one of the higher profile (out of high school) guys as a potential trade up target. If Hampton, Maxey or Anthony fall out of the top 10 maybe DA offers #17 + #26 + Semi? to move up? This would clear up some of the roster crunch and bring in a player to complement Marcus off the bench.