Man, you guys are mucking up a really simple process. Rookies upgrade their specific positional skills really cheap but upgrade their physical skills(STR, SPD, AGI, ACC) at a pretty expensive rate. Understanding that, start with physical height and weight. Bigger guys are more likely to have high STR. STR plays into everything from catching to hit power to trucking to press coverage. ACC and AGI are all about moving quickly over short distances in space so they're important for literally every position except the K and P. SPD is maybe the least important of the 4 except for CB, HB, and OLB. It helps many other positions but, even for WR, it's not critical to being successful.
So find your potential draft pool starting with size and scout only the physical skills. This will narrow down your list quite a bit. Then start scouting the attributes most important to you. This, combined with lotusfathers draft guide, should make you aware of the know studs as well as the hidden gems that can grow into beasts.