From my experience, driving leads to more opportunities, while IS helps to capitalise on them.
If a PG has great driving skill (say, prominent or even better) and poor IS (say, awful or poorer), would he still score lots of points when playing LI or LP?
I always think only IS would help to score, especially playing LI / LP ; However, driving would make the players shoot better, hence better FG% (and more free throws if the opponent players commit fouls).