Defining, judging or grading GM's needs to be defined by what you consider successful.
There is a big difference between on the field and off the field success. Then there is the time factor. Last 3 years? 5 years? 10 years? More?
I see Veach is #2. That is laughable to me. He got lucky and Reid fell into his lap. He did trade up for Mahomes. Quick - someone name his 3rd best move.....
The Dallas Cowboys are the most valuable sports franchise in the world. Their GM should get big kudos for that. But on the field success???
Belichick has a bunch of Lombardi's, yet he isn't in the top 10?
Either drafting Creed Humphrey who is the best C in football or the Orlando Brown trade securing the offensive line for Mahomes while he does all the work. I am not disagreeing but those are my guesses.
Honestly I would argue the same thing about the Packers as Rodgers has been carrying a fairly bad roster for years now. The Bengals basically drafted Burrow and Chase and then have basically had to free agency their way through everything else.
The Bills at 4 I disagree with the hardest. They had presumably a top 5 QB on a rookie deal and the sum total of their accomplishments on said deal is 2 divisional round losses and a single conference championship game appearance. I am sorry but if you a top 5 GM with a top 5 QB, I expect better results over the course of the rookie deal.