It's definitely possible. Saquon Barkley didn't test well in HS either. But guys like that aren't common. A large majority of players don't make some huge athletic leap from what they were in HS. I wouldn't assume he's a mid 4.5 guy - but we'll see.
I think you're making way too big of a leap here.
Hill ran a 4.98 in HS at 212 lbs. and had a 78.6 SPARQ. He was listed at 238 this year at Miami.
Hill stayed with Akers on that run because Akers was changing directions and fighting through a tackle while Hill was running untouched on a...