How could anyone not know this? LOL
OK, to be fair, I can see getting the AFC South or the NFC West a little confused, but how does anyone at least not know that the Vikings/Bears/Packers/Lions are in the same division or the Steelers/Browns/Bengals/Ravens are as well.
The NFL is so brilliantly constructed and organized - and makes so much sense - that these divisions have tremendous meaning and implications each and every week. Unlike basketball, hockey or even baseball, which are so much more haphazardly thrown together.
Division games in the NFL are HUGE. Conference games are also important, and even cross-conference games are critical because divisional teams play essentially the same schedule (other than two games).
Tannehill and McCoy are football idiots if they don't know this. I guarantee you Andrew Luck knows them, as did the Mannings.