Since the current thread on Greg's book concentrates on colo(u)rs and markings, I'll not intrude.
Cross-checking the Osprey book with Grub Street's
Above the Lines, it appears the top D.VII aces (with few exceptions) were:
Lowenhardt 36
Buchner 35?
Udet 32-34
Bäumer 21?
Noltenius 20-21
Friedrichs 20?
Hantelmann 20?
Beaulieu 17-20
Fruhner 18
Lorzer 18
Veltjens 17?
Bolle 16?
The main omission is Rumey of J.5 (not assigned to a JG) with at least 16 in D.VIIs, roughly based on the chronology of his victories. As Greg has noted, inexact dates of D.VII conversion and use of other a/c (Bäumer's Pfalz D.VIII ferinstance) tends to complicate things.