During the Roy era (up until last season):
Head to head - Duke 18 -12
Overall records - Duke 408-96, UNC 398-115
Tourney Records - Duke 31-12, UNC 42-10
Since 2011 (reflect OAD)
Head to head - Duke 11-5
Overall records - Duke 203-51, UNC 202-61
Tourney Records - Duke 14-6, UNC 21-6
Aside from head to head, Duke's overall record surprisingly not much better than UNC over this time; the tourney records are obviously not a surprise given UNC's consecutive runs to the final and Duke shitting the bed 3 times this decade.
If these records are to be used as a referendum on the OAD vs. Roy recruiting style since 2011, I don't think you can say Duke has taken the wrong approach. Consider the shit luck encountered during this period - major injuries in 2011, 2013, 2016 & 2017.
With good health, there is no reason this current Duke squad should not win 30+ games and be positioned to make a decent tourney run. Even with all the flaws, there is too much talent for this team to be playing so poorly.