I would argue that Philly making the Super Bowl last year, and being one of the heavy favorites to represent the NFC again is probably evidence that the AJ Brown move worked for them. I mean, the year before he got there, Hurts was 8-7, threw for 3,100 yards, 16tds, 9 picks and had a rating of 87.2. Then AJ Brown shows up and he goes 14-1 with 3,700 yards, 22tds and 6ints and a 101.5 rating and a trip to the SB. The downstream effect was that Smith went from a guy with 64/916/5 to 95/1196/7, and Miles Sanders went from 62.8 rushing yards per game and 0 touchdowns to 74.6ypg and 11 touchdowns.
It's harder to know what Miami would have accomplished last year due to Tua's injuries, but in 12 games before Tyreek Hill the season before, he went 7-5 with 2,650 yards, 16tds, 10 ints and a rating of 90.1. Add Hill to the mix, and in 13 games, he went 8-5 with 3,500 yards, 25tds, 8ints and a 105.5 rating. Those numbers would have been even better if he wasn't allowed to play his last game completely concussed against Green Bay and throw 3 interceptions. Like DaVonta Smith in Philly, when Hill got introduced to the mix, Waddle went from a 104/1,015/6td rookie year to 75/1,356/8 second season, nearly doubling his yards per reception because you can't cover him one on one.
If you have skill position weapons and a great offensive line, you could let Mac walk and replace him with just about anyone and be successful, at least that's what Brock Purdy and Kyle Shanahan told me.