You're right, but also they can't put him in wild positions. The interception he threw was against a blitz with no hot routes. That's an insane thing to place any QB in. None of them sight adjusted. The OC's plan against blitz shouldn't be for Lamar to be magical, escape, then throw the ball down the field.
That's what happened against the Lions. That's what happened against the Chiefs today. At least the Bills will have Shakir or Cook as an outlet. At least the Lions will go max protect.
You can't say the statement about a HC change not mattering. That's nowhere near true. Harbaugh absolutely is a problem in the sense that he's a net negative in the strategy department. He can't do like Andy or Campbell and consult on offensive strategy. He can't do like McDermott and take over the defense. The Ravens don't do like the Eagles and remove his ability to choose coordinators. A HC would improve the team just based on them because able to commit more tactical brain power to either offense or defense. He can say vague things, but he can't do the specific fixed in the same way a former OC/DC can do. That's why he had to bring it Dean Pees last year as a consultant and Pagano this year as a consultant for Orr. He's a former special teams coach on a team with mediocre special teams. Special Teams coordinators are essentially there for vibes. The team's vibes are cooked which should be his actual specialty.