He was the best in the league at finding NHL players, i.e. got the most NHL GP out of his draft picks. As seen in that article. You know your example's silly, I know you do.
Well if thats your premise for a draft than good luck with a team full of tweener talent along with Vanek and Miller.
1998:
1st round #18 Kalinin...players drafter after: Regher, Gagne, Gomez
2nd round #34 Andrew Peters, players drafter after (Erskine, Vaananen, Fisher, Ribero
6th round #164 Kotalik - yup good pick at that spot
1998:
1st round #20 Barrett Heisten (a total of 10gp), players drafted after Boynton, McCarthy, Havlat
2nd round #35 Bartovic (50gp), players drafted after Semenov, Auld, Commodore, Leopold, Adam Hall
5th round #138 Ryan Miller - very good pick at that spot
2000:
None of the top 5 players drafted (#15, 48,111,149,213) have played a single NHL game
Paul Gaustad picked in the 7th round at 220 but you can hardly tell me this was more than a coincidence considering every single pick before that was screwed up
2001:
1st round #22 Novotny, players with more GP drafted after him: Gleason, Kraijeck (including him should show what bad pick that was), Woywitka, Steckel
2nd round # 32 Roy, player drafted after him: Jackman, Tyutin, Cammalleri
the other 2nd rounders in Thorburn and Pominville were pretty good considering what was left (well yeah Plekance, Ehrhoff, Bieksa and Sharp but most teams failed to look at them)
2002:
1st round #11 Ballard, drafted after that: Eminger, Semin, Higgins, Gordon
1st round #20 Paille, drafted after that: Babchuk, Bergenheim, Eager, Steen, Ward, Slater, Stool, Daley, Greene, G. Campbell
6 further picks from round 3-7 combined to 14 gp (all from Hecl)
In round 8 they got Wideman which is fantastic in a vacuum but looking that all 6 before bombed it looks like a "got lucky" pick
2003:
one of the best drafts ever in which the Sabres held the 5th overall pick, used on Thomas Vanek. Players drafted after that: Suter, Coburn, Phaneuf, Carter, Brown, Seabrook, Parise, Getzlaf, Burns, Kesler, Richards, Perry, Eriksson, Bergeron, Carle, Weber, Crawford, Howard
2nd round, #65 Fabry (zero NHL games played) picked after that Fraser and Carcillo
2nd round #74 MacArthur - good pick just like Hejda in the 3rd.
2004:
1st round #13 Stafford - drafted after that: Dubnyk, Radulov, Chipchura, Korpikoski, Zajac, Wolski, Meszaros, Schneider, Schultz, Fistric, Green, Bolland, Bickell
2nd round # 43 Mike Funk (9 NHL games played), players drafted after that: Comeau, Booth, Grossman, Dubinsky, Goligoski, Krejci, Prust
3rd round #71 Sekera - very solid pick (Van grabbed Edler at 91, DET took Franzen at 97)
6th round #176 Kaleta - played 348 games but "just" an enforcer and nothing to write home about.
As a conclusion I would say during Benning tenure as the Sabres head scout, Buffalo drafted 2 very good impact players in Vanek and Miller. Besides that he has been solid in finding some talent for the 2nd-4th line (mainly bottom 6) and some #3-4 defensemen. Dont get me wrong, this is far from being a bad result but I wouldnt call that outstanding drafting either.
Going only by games played is a bad way to judge draft success. If get a 4th liner in the 2nd round that is playing 400 games but in a trade would only get you a 5th or 6th rounder, is that still great drafting?