You had three ten-win teams (the surprising Broncos, the Seahawks, and the defending champ Raiders). You also had an OK KC team that finished 8-8, and you had Air Coryell finishing 7-9 (however, they did beat SB-bound Miami and the Bears. They also lost the four games in the division to Denver and the Raiders by seven points or less).
Even with that, they probably should have pulled the plug on Air Coryell at that point and started over, but Don got to stay another year and a half before being let go on October 29, 1986 by owner Alex Spanos.