One of the things we've learned from this brief season is that Joe Burrow was, is and always will be the entire offense... unless, perhaps, they ditch Zac *or* force him to pass off the offensive play calling to someone else (probably not Callahan, he has to be part of the problem, right?).
The fact of the matter is I'm perfectly ok with Joe being the be-all, end-all. I've pictured Joe as a future Peyton Manning type since I started paying attention to him during his last college season (meaning I saw him as a guy who was going to call his own plays eventually). Just get the kind of offensive coaches who will teach and support him, not the type who vacillate between dictating what he's going to do and coddling him when he instead needs direction.