Legends isn't trusted.
That said, just like Global and other bad "authenticators," they occasionally slapped their name on legitimate pieces. I think this might be a limited edition art print by Andrew Goralski that was co-signed by Payton for the Pro Football HOF, in which case it should be authentic. Just don't put any value in a Legends backing.
Based on this and the Riggins post you made, I think you might want to focus more on the signatures and less on the COAs. In general, COAs aren't worth much. If you're going to focus on COA's, stick with the established ones for sports (Upper Deck, PSA/DNA, Beckett, Steiner, Tristar... maybe even Leaf). COAs where a reputable company witnessed the item being signed are the most reliable (JSA Witnessed Protection Program, Beckett Witnessed, PSA/DNA In the Presence Of, Upper Deck, etc.). But at the end of the day, even the big names make mistakes so evaluating the actual signature is the best strategy.
Thank you so much for the advice the Walter to me looked legit the COA just got me nervous to pull the trigger. I appreciate the help!
Looks good to me.