I compared him to the most MSU 3-point attempts per game I could find in the last 10 years. Then compared him to some of the more popular NCAA 3-point shooters. And finally compared him to a combination of MSU's top two three point shooters each of the last 10 years.
Henderson averaged the most per game since 2009. He shoots about as good as Barry Stewart but shoots more than record holders like Stephen Curry or JJ Redick.
Marshall Henderson -- 394 attempts, 10.94 per game (leads the nation), 35%
MSU leaders
Ravern Johnson 2011 -- 206 attempts, 7.4 per game, 40%
Dee Bost 2012 -- 217 attempts, 6.6 per game, 35%
Barry Stewart 2010 -- 222 attempts, 6.2 per game, 35%
Random NCAA comparisons
David Holston 2009 -- 394 attempts, 12.3 per game, 37%, 394 is the most attempts in a season I could find
Stephen Curry 2008 -- 369 attempts, 10.3 per game, 44%, holds single season record for 3-pt made
JJ Redick 2006 -- 330 attempts, 9.2 per game, 42%, holds career record for 3-pt made
Chris Lofton 2008 -- 307 attempts, 8.5 per game, 38%, holds SEC career record for 3-pt made
Keith Veney 1997 -- 320 attempts, 11.0 per game, 40%, hold record for most 3-pt made in a game
MSU top two leaders per season
Bowers + Frazier -- 386 attempts, 12.9 per game
Stewart + Ravern 2010 -- 436 attempts, 12.1 per game
Bost + Steele 2012 -- 395 attempts, 12.0 per game
Henderson averaged the most per game since 2009. He shoots about as good as Barry Stewart but shoots more than record holders like Stephen Curry or JJ Redick.
Marshall Henderson -- 394 attempts, 10.94 per game (leads the nation), 35%
MSU leaders
Ravern Johnson 2011 -- 206 attempts, 7.4 per game, 40%
Dee Bost 2012 -- 217 attempts, 6.6 per game, 35%
Barry Stewart 2010 -- 222 attempts, 6.2 per game, 35%
Random NCAA comparisons
David Holston 2009 -- 394 attempts, 12.3 per game, 37%, 394 is the most attempts in a season I could find
Stephen Curry 2008 -- 369 attempts, 10.3 per game, 44%, holds single season record for 3-pt made
JJ Redick 2006 -- 330 attempts, 9.2 per game, 42%, holds career record for 3-pt made
Chris Lofton 2008 -- 307 attempts, 8.5 per game, 38%, holds SEC career record for 3-pt made
Keith Veney 1997 -- 320 attempts, 11.0 per game, 40%, hold record for most 3-pt made in a game
MSU top two leaders per season
Bowers + Frazier -- 386 attempts, 12.9 per game
Stewart + Ravern 2010 -- 436 attempts, 12.1 per game
Bost + Steele 2012 -- 395 attempts, 12.0 per game