NFL Connections #19, Answers
The full solution: all four groups and the 16 names, sorted from the easiest group to the trickiest.
Electric return men
Devin Hester, Dante Hall, Cordarrelle Patterson, Brian Mitchell
Dual-threat QBs
Michael Vick, Lamar Jackson, Randall Cunningham, Steve Young
Iconic safeties
Ed Reed, Troy Polamalu, Sean Taylor, John Lynch
Slot receivers
Wes Welker, Julian Edelman, Cole Beasley, Hunter Renfrow