Gus was JAG on the team prior to Lamar coming in. Gus pretty much never touched the ball without Lamar. He was given an opportunity because Lamar opened the run game.JK and likely Gus both would play well with another offensive system/QB. Bateman, Andrews, both the same thing. In fact, Bateman may actually be better in a different system honestly. Hollywood would probably be lesser off, but Proche would step up in a traditional offense. Honestly the only guy I'm seeing a big drop off from would in fact be Hollywood.
JK was CFBs leading rusher on RPOs and CFBs leading rusher out of the shotgun. He was absolutely drafted with Lamar in mind.