It’s important within an offensive line to have talent. It’s important within an offensive line to have quality coaching. But equally important is having cohesion within a five-man group—really, within a nine-man group, or however many offensive linemen you may have and would need to play.
The Pittsburgh Steelers had a hard time with all phases of the offensive line last year, but especially in terms of cohesion. Not only were they playing four new starters, including three players who were completely new to the team, two of whom were rookies, but they also shuffled the projected starting lineup, just before the season, due to injury.