Mike Vrabel's teams were near the bottom of the league in passing yards and attempts all 6 years as head coach of the Titans.
My impression of Vrabel is he wants to play conservative, ball control on offense, limit turnovers and win with defense. This has been the Bears model for the past 40 years, resulting in one SB win and mostly unwatchable football in just about every other season. I'm tired of that movie.
I don't think this style of play will allow the Bears to be competitive in the division. The Packers, Vikes and Lions all have electric offenses. The talent at the skill positions that all three of our division rivals have is just off the charts insane. The Bears will go down in flames if they're the only team in division trying to win with ball control and scores of 20 - 13. That style of play also doesn't maximize Caleb's considerable skill set.
Vrabel is the safer bet with the higher floor but also the lower ceiling. Johnson is the risker play who has a lower floor but a much higher ceiling.
I'd prefer to see Johnson as HC with Saleh as DC but acknowledge this road has considerable risk. Johnson has been around the best OL in football for multiple seasons now. If he were the HC maybe he'd bring an ability to identify quality OL players in the draft.
I really do feel the next HC hire is monumental for the Bears organization. I could see Caleb walking away from the Bears in year 4 if they screw up this next hire and continue to be an embarrassing, non-competitive team.