100 speed basically is meaningless in the nfl. the 40 or even the 10 is what matters. eaton's pr is 10.21 and, regardless, there aren't that many guys in the nfl who can run faster than that. i would argue that, given his 10.2 100 speed and the fact that he can jump so well (that requires explosiveness) and throw the shot so well (that requires speed), yes, he is faster than most guys (speed position players) in the nfl.
i agree that gatlin, on paper, seems to have a lot of the raw talent to make it in the nfl:
On March 13, 2008 Gatlin performed at the Titans' NFL pro day. His numbers were as follows: 4.45 and 4.42 in the 40-yard dash. Had a 40 ½-inch vertical jump, 11-foot (3.35 m) standing long jump, 4.4 short shuttle, 7.36 cone drill and 12 reps in the bench press. The former Olympic sprinter did not get signed by any NFL teams.
however, these numbers don't measure hand-eye coordination (can he actually catch the ball?), how much he can take getting hit and what kind of football iq he had (he hadn't played since high school).