There are tons & tons of HS prospects who are classified as an ATH, because they do not project to a certain position. 1 thing about it is that once those players reach the collegiate level they are stripped of that ATH title. In Alabama's Blake Sims case that's another issue, because he has no true collegiate position.
Blake Sims' position is listed as "athlete" in Alabama's media guide.
He was a four-star prospect who passed for 2,288 yards and ran for 863 as a senior at Gainesville High School
Tonight vs Ole Miss he got looks at RB where he looked very appealing to the eye. The ironic part about his situation is if he is or does end up being projected as a RB next year, he will have a long list of guys to compete with for playing time(Lacy, Fowler, Hart, Howell, Calloway)
I believe his best shot as being projected to the NFL would be to slide over to WR ala Russell Shepard.