CINCINNATI — Even on an aluminum bench on the sideline at Paul Brown Stadium, the Broncos’ offensive line stays in formation. Left to right, facing the same direction, shoulder-to-shoulder from tackle to guard to center. You can imagine them walking down the street or waiting in line at the grocery store always in order and never apart. So when the skeptical questions came at them even before this season started — can Denver’s front five keep standing long enough to keep a quarterback alive?