NFL Connections #26, Answers
The full solution: all four groups and the 16 names, sorted from the easiest group to the trickiest.
Indianapolis Colts greats
Peyton Manning, Marvin Harrison, Edgerrin James, Robert Mathis
Tennessee Titans greats
Steve McNair, Eddie George, Bruce Matthews, Derrick Henry
Houston Texans greats
J.J. Watt, Andre Johnson, DeAndre Hopkins, C.J. Stroud
Jacksonville Jaguars greats
Fred Taylor, Maurice Jones-Drew, Tony Boselli, Mark Brunell