I am not concerned about Duke not having a Consistent #3 scorer. Last season's team didn't have that either, it was done by committee. Last season Duke could count on Flagg and Knueppel to score consistently, then the rest of the guys would balance the rest of the scoring. Duke will be fine with Cameron and Evans leading the charge on the offensive end with Sarr/Ngongba/Khamenia/Foster/Cayden/Brown/Harris (hope he gets back in the rotation) balancing the rest of the scoring.
As far as the concern on not having a Pure PG, imo Duke will be fine here too. Coach Scheyer and Nolan Smith alternated bringing the ball up during the 2009-2010 National Championship Season. Neither Scheyer nor Smith were Pure PGs. Scheyer's Experience can pay dividends for both Foster and Cayden (combo guards).
Arizona, UConn, Duke, Houston, Michigan, and Gonzaga are the best teams in the country at this point in the season. All of them still have plenty of time to Evolve and Improve. This is A Very Strong Season for Men's College Basketball.