I think (not 100% positive) our previous head coach has inherited every starting QB for his entire head coaching career.
I don’t disagree with your point but I would think most new head coaches don’t go to teams who are already established with proven QB’s in their prime. It really depends on how you define success and how long the coach has to achieve.
This year you have Johnson inheriting Caleb, Vrabel inheriting Maye, Coen inheriting Lawrence, and then Carrol, Moore, and Glenn will have to find their QB’s.
My bet is none of them experience much success anytime soon if ever. I also bet Moore would give his left nut to have inherited Dak v. what he has.