There is no exact science to putting together a unit, either on the offense or the defense. Generally speaking, one would think that you want to invest higher-round draft picks into the positions deemed to be of higher value, but it doesn’t have to work out that way.
Most thought that the Pittsburgh Steelers should invest in their offensive line early this year in the 2021 NFL Draft. Instead, they used their first two picks on a pair of skill-position players in running back Najee Harris in the first round and tight end Pat Freiermuth in the second.