I would say that all fits together though.
They determine the 75 players on their list based on system fit, cultural fit, upside and physical attributes.
When it comes to ranking them though, they project what role(s) they would play year 1 and year 2, and compare that to what they already have on the roster. The more roles you project to play, at a high enough level, and compared to the marginal increase you get on the roster, the higher you’re ranked. I’d expect having multiple roles has a huge value to the team because it frees up a roster spot to use somewhere else. I think this is easier to see in their free agency salary structure - they’re willing to pay top money for the best at their position (Brady, Gilmore, Gronk, Mason) or for very good players who fill multiple roles that save roster spots (DMac, Hightower).