If a guy can actually feel pressures instead of being oblivious to it he can indeed help his line by eluding the pressure, that can make his line LOOK better by avoiding a sack. If a guy can read a defense better than another guy that also can assist an o-line, possibly by throwing it quicker (lowering blocking time) or switch out of a pass to a run or vice versa, that can help out line issues as well. Better play at a position can IMO indeed help out a team, an o-line is part of a team, so better QB play can help improve line play. Notice the key word HELP.