I'm not sure, but I have jotted down some notes from the past (same team, so apples to apples as far as what defense they face, etc):
From my Maryville team a couple seasons back:
Guard A: 58 SPD, 46 BH, 97 PER. 47.0% as a sophomore, 47.6% as a junior, 49.5% as a senior
Guard B: 47 SPD, 54 BH, 83 PER. 44.8% as a sophomore, 47.0% as a junior, 39.8% as a senior
Guard C: 81 SPD, 65 BH, 72 PER. 36.3% as a sophomore, 39.9% as a junior
A was a SG his whole career, C was a point guard his whole career. B played SG for two years and then split between SG and PG his senior year. A had the highest distro of the three
From my Whitworth team last year
Ware: 92 SPD, 72 BH, 93 PER. 34.7% as a junior, 39.3% as a senior
Gilyard: 54 SPD, 57 BH, 89 PER. 39.3% as a junior, 41.5% as a senior
Ware came off the bench at PG, Gilyard played SF. Distro was the same.
From my Kentucky Wesleyan team last year
Cullens: 57 SPD, 72 BH, 82 PER, 41.1% as a sophomore, 47.8% as a junior so far
Stanhope: 50 SPD, 76 BH, 90 PER. 39.1% as a junior, still under 100 attempts as a senior (but shooting 49%)
Neither play PG. Cullens has more distro.
I only included folks with 100 or more attempts, and I obviously listed the stats that people think affect three-point shooting. I can draw no conclusions except that PER is important and not-being-a-PG is important.