It’s often been said that NFL general managers earn their money on days 2 and 3 of the draft, and that sentiment has a certain intuitive appeal. In looking at the selection of first round picks in the 2017-2019 drafts, there’s actually not a ton of divergence in opinion between the commentating “draftniks” and the professional scouts and GMs working for NFL teams. The pros tend to pick a little better than the commentators, but using a consensus commentator big board would absolutely get you into the same ballpark as the pros in the first round.
After that, things tend to get more fuzzy, however, as the talent pool expands and the depth of evaluations contracts.