Simply because every team has their own set of talent evaluators.
How a draft board works is like this: (somewhat)
1. Scouts and FO meet after the season to go over players and give them a grade.
2. Lists by each position are created and stacked by grade given.
3. Then an overall "bigboard" is built regardless of position.
4. players are then trimmed out based on medical, off the field, positional fit (ex. a 4-3 end for a 3-4 team) and lack of need (I guarantee Saquon Barkley is not on the Rams board)
5. After they get down to around 75 to 125 players. Players with similar grades get moved around according to need.
Example:
Dorance Armstrong Jr (Edge Kansas) I have a grade on him of 6.8
Donte Jackson (CB LSU) His grade is a 6.9
There is really no discernible difference between the 2 grades. They (according to my grading system) are contributors as rookies with a chance to start. So on my Make Believe Team that has a giant hole at edge rusher, would put Armstrong above Jackson. And that is who we (as part of the deciding group in my make believe teams warroom) would draft.
And if I was so flush at CB , I probably don't even have Jackson on my board.
Lastly if a player everyone generally has as a 1st or early 2nd round talent like Jaire Alexander or Oliver, slides into the middle of the 3rd round and no one has traded up for him, then he has an issue the media has no idea about or he was a product of the media hype machine and wasn't all that of a prospect to begin with.
Don't waste your time looking back, you're not going that way. - Ragnar Lothbrok
