S Sydney Brown, Illinois
The Chiefs tend to flex their safeties around and play them everywhere nowadays, as seen by the fact that they've put Thornhill/Reid/Cook in all kinds of different spots on the field. If they continue doing that, they're going to need jacks-of-all-trades types of safeties in the draft. And my guess is that Juan Thornhill is moving on to another team for a big payday, so they'll be in the market for at least a third safety, if not a starting safety if you're not a big believer in Bryan Cook.
Sydney Brown (brother of
Chase Brown!) is not that guy. Brown does not have the size or the attitude to play up in the box, and he lacks the physicality to man up on tight ends. What Brown has, is loads and loads of elite athleticism and fantastic ball skills.
If the Chiefs decide to slot guys into roles again at safety, then Sydney Brown is an ideal cover-1 deep safety in the mold of Rookie Year Juan Thornhill. He can cover gigantic tracts of land against the typically-smaller receivers that run those routes. There aren't many WRs who can beat him in a straight line race and if the ball is up for grabs, he can make a superior effort for it.
It's a limited role in a Spags defense, but one he could deploy effectively if called upon. He makes sense to me as an early pick on day three.