I think that you brought up something important, class size consideration.
Son went to a large HS but in an excelerated program (could grad early) with no more than 30 per class. He was very overwhelmed by the 40K+ D1 when we went to visit, the academic advisor told us some lecture classes had as many as the amount of kids in son's school.
One of his considerations was smaller class size at CU.
Another thing you brought up was SAT/ACT scores. My son's scores also didn't match his grades (though not bad), partly because it was taken with half an effort at the time and not ONE coach cared. Since most of the better academic programs base their class difficulty on such scores, he might have struggled a bit more than he did at first. Like many other players, he opted out for an easier course of study and I think he is sorry he did.