I agree with you on the 3, but I don't think PG's are a priority to be honest. It's not a great comparison, but I feel like PG's are kind of the RB's of the NFL - it's easier to find a "steal" at PG than any other position. Teams that are stacked at other positions can still win titles with mediocre PG's. I'm new here but I bet ya'll have had the debate during the CP3 years of "when's the last PG driven team to win a title?".
So I'd rank positions of importance in today's NBA as: Small Forward, Shooting Guard, Center/Power Forward (tie), Point Guard. I might even say that a slashing 6th man type like Ginobli or Harden is MORE important than your starting PG.