Good analysis. Nobody, of course, wants a slow running back, as "speed kills." But, IMHO, the straight 40 time is one of the most overrated statistics. Really, in game situations, unless you're a WR running an occasional streak, nobody ever runs 40 yards in a straight line. (Please, unless you sincerely disagree with this, spare me the example of the rare exception. Lol) personally, I think quick, 5-yards bursts are much more important in the game of football.
It's similar to when friends tell me, "So-and-so high school has two linemen who are 6-5/ 295. Akron should sign them." Yeah, well those linemen are fat, not muscle, can't bend @ the waist, can't come off the line, can't move their feet and don't cherish contact. There are so many intangibles to being a good football player.
Kid looks plenty fast enough & like a good get.
Go Zips!