They are also 11-5 for a reason, and it's not the qb carousel they've been riding all year. Teams with a pedestrian defense couldn't play in that division with a third string qb and make the playoffs. Can't put too much value in those rankings.
You are absolutely right, they are 11-5 for a reason. They started 9-1...the reason they are 11-5 is because they're on their 3rd string QB --Ryan Lindley. They just got lucky Palmer / Stanton held out long enough for them to clinch a spot early and limp into the playoffs.
It is not going to be pretty for the Cards on offense.