Maybe it's the Holmgren legacy -- like in Seattle, when the pass offense is clicking they look to spread it around. Koren has shown himself incapable of being a Moss-like go-to guy. to much ressure maybe. But with Engram and DJax taking away some of the pressure (coverage), he gets his chances.
In GB, Driver has been injured. Now that he's healthy, Favre seems comofrtable enough with Ferguson and Walker. And there's always Franks and Walls (but is Walls out now?).
But I agree, Ahman is their best chance for success on offense.