I go with probability, and probability says its highly unlikely. So we can take Glenn, and he can be a good coach and the odds are drastically in favor that he'll never sniff a superbowl without inheriting a team that already has a franchise QB.
What do you base your opinion that probability says its highly unlikely? What numbers support that position?
We just gave you 3 or 4 HoF QBs, one that is arguably the GOAT, that developed under defensive head coaches. And at least three of them won Super Bowls with their defensive HC in charge. And one of them won 7 Super Bowls. And Matt Ryan would have one if they had not blown a 28-3 lead to another QB that was developed by a defensive HC.