NFL Connections #96, Answers
The full solution: all four groups and the 16 names, sorted from the easiest group to the trickiest.
Defenders of today
Myles Garrett, Micah Parsons, Sauce Gardner, Fred Warner
2010s defenders
J.J. Watt, Von Miller, Aaron Donald, Luke Kuechly
2000s defenders
Ray Lewis, Ed Reed, Champ Bailey, Julius Peppers
1990s defenders
Derrick Thomas, Cortez Kennedy, Rod Woodson, John Randle