check myself on that. I want to do some research on Big 12 freshmen last year and how much they started/played/scored. I don't think there were many FR among the top scorers in the league last year.
I think you are spot on. An 18yo freshman, no matter how talented or highly projected for the draft, will be acclimating to a whole new level of ball going to the top of the college BB world in the Big 12.
These guys will be in a battle against some VERY experienced players for starting spots. It could easily be if they end up starting consistently, it will likely come later in the season after some maturing and growing pains.