NFL Connections #66, Answers
The full solution: all four groups and the 16 names, sorted from the easiest group to the trickiest.
Modern shutdown corners
Darrelle Revis, Richard Sherman, Patrick Peterson, Jalen Ramsey
Ball-hawking safeties
Ed Reed, Troy Polamalu, Earl Thomas, Minkah Fitzpatrick
Classic shutdown corners
Deion Sanders, Rod Woodson, Mel Blount, Mike Haynes
Hard-hitting safeties
Ronnie Lott, Steve Atwater, John Lynch, Sean Taylor