Not necessarily just from your PG- having a good passing SG helps tremendously as well. As others have said, DR is a big skill if you're looking for a good LI. While having all of your guys with high IS will dramatically help your FG% inside the arc, all that does is ensure once the ball gets there, the chance of conversion is high. If your FG% wasn't high, then that might be something wrong with the game engine. Having team offensive flow at "inept", combined with, like you're saying, not your ideal 2pt/3pt shot ratio, leads me to believe your issue lies more with getting the ball in a position to score inside, rather than intentionally looking for a 3pt shot.