Yeah I agree, the 4th one is not assured at all. Next week the Colts play the Raiders and the Texans play the Titans. If Raiders and Titans both win, our 10-7 chances skyrocket.
Tonight Broncos losing to the Patriots would be amazing but that's not expected. They them finish against the Chargers and Raiders... I think it's decently likely they slip up somewhere over those 3 games but no guarantee.
Jaguars losing 2 of their last 3 against Bucs, Panthers, Titans, that is the least likely result IMO.
Although the NYT playoff calculator really likes our chances. I input the current game results, and also put us beating the Pats and losing to the Dolphins. Their calculator gives us an 83% chance of being a wildcard in that situation.