I'd give him the benefit of the doubt if he actually hit on a few picks outside of Luck. If you throw out Andrew Luck's success, on the belief that 32 out of 32 GMs pick him first in 2012, this is what Grigson has done
2012
2- Coby Fllener (no longer on team)
3- Dwayne Allen
3- TY Hilton (2 pro bowls)
5- Josh Chapman (no longer on team)
5- Vick Ballard (no longer on team)
6- LaVon Brazill (no longer on team)
7- ZJustin Anderson (no longer on team)
7- Tim Fugger (no longer on team)
7- Chandler Harnish (no longer on team)
2013
1- Bjorn Werner (no longer on team)
3- Hugh Thornton
4- Khaled Holmes (no longer on team)
5- Montori Hughes (no longer on team)
6- John Boyett (no longer on team)
7- Kerwynn Williams (no longer on team)
7- Justice Cunningham (no longer on team)
2014
1- Traded for Trent Richardson...who is no longer on team
2- Jack Mewhort
3- Donte Moncrief
5- Jonathan Newsome (no longer on team)
6- Andrew Jackson (no longer on team)
7- Ulrick John (no longer on team)
2015
1- Phillip Dorsett
2- D'Joun Smith (no longer on team)
3- Henry Anderson
4- Clayton Geathers
5- David Parry
6- Josh Robinson (no longer on team)
6- Amarlo Herrera (no longer on team)
7- Denzell Goode
20 of 30 picks not on the team
A combine 2 pro bowls from those 30 picks
7 starters from the last 4 years