The Denver Broncos have had 13 men who have held the title of general manager, many of whom were also listed as something else during their time as GM. I will fully admit that I do not know much of the history of these GMs. I am reporting the information that I have found on pro-football-reference.com.
Some of the folks with whom I have interacted on Twitter have noted that a few of these GMs had little to no control over player decisions. Without digging too deeply into the history, I can’t say one way or the other, but I welcome the input of those who have knowledge of the roles that each played or didn’t play in the history of the franchise.