Comparing draft picks across GMs is a little bit of a fools errand if you ask me. So much depends on where the team picks, the strength of the draft etc. That said, a simple analysis of picks outside of the top 10 (historically all top 10 players play at least 100 games with few exceptions) shows that Nonis did well based largely on that 2004 draft, Benning did ok based largely on the 2014 draft, and Gillis did the worst. But the difference is so small. Basically, by percentage of picks over 6-7 years Gillis picked 2 fewer players that went on to play more than 100 games. To say that that is franchise altering is a stretch, to be polite. One of those extra players is Jonah Gadjovich and Benning traded away two others...
Picks below top 10 to play more than 100 NHL games.
Nonis: 2004 (4), 2005 (1), 2006 (1), 2007(0)
Total: 6 of 23 (26%)
Gills: 2008(0), 2009(2), 2010(0), 2011(0), 2012(2), 2013(0)
Total picks: 4 of 35 (11%)
Benning: 2014(3), 2015(2), 2016(0), 2017(1), 2018(0), 2019(1), 2020(0)
Total picks: 7 of 40 (17%)
Alvin: 2021(0)*, 2022(2)*, 2023(1.5)*, 2024(0)*
Total: 3.5 of 24 (15%)
*projected - being conservative