I agree with girt, I just checked, after 7 games, my F IQ player is a C-, so the frosh catches up near immediately with some practice minutes. If you are talking long term, the single best way to get high IQ's is to devote lots of time to practice, of course, that is at the expense of ratings improvement, as many things in this game, best is finding the right balance between team and ind practice.
I look at knowing my sets in a recruit, much like GPA or even FT%, as a bonus, but I seldom recruit based on any of those factors - best is to recruit for the cores and potential, and again, we can't get everything in a recruit, so the key is to find the right balance - if somehow that player includes some set knowledge and a high GPA, all the better.