He was not a good 2nd stringer because that means he is one play away from having to try to carry it 20 times a game which would not be good for someone that the defense knows can't make plays.
I feel a 2nd stringer is a starter waiting his turn.
It isn't me that acts like Cunningham is so much better than he is and makes comparison to Gurley and Faulk. That would be other fan. I would compare him with guys like June Henley an Gerald Moore and Brian Leonard.
By those standards, he may edge him. I wouldn't even put him in the same class as Robert Holcombe, Trung Canidate, Amp Lee, or Gordon
By the way, trung had 6 touchdowns and 5 plays over 20 yard in his one year he was healthy so he did more in 1 year than Cunningham did in 4 years and is considered one of the biggest busts in Rams drafting history. That should put it in perspective the lack of playmaking Cunningham had.
On Tavon, I do agree with you that he has not lived up to his draft pick, asset of an 8th pick in the draft, but in comparison to Cunningham has delivered so many more plays. I know you can't compare a WR to RB in big plays, but he has even more running plays of 20+ yards, 10 of them. Plus, he has delivered 20 touchdowns.
So in judging the 2, one has much more big play ability than the other regardless of the draft status. Tavon is not overrated because every fan thinks the draft pick was not of value. Just because he is a better player than Cunningham doesn't mean the pick was a good one. It is 2 separate things. It was a bad draft pick.