I'm very high on Seattle and Detroit as well. They've added bigger pieces than we have. And they're on the rise. They're my picks to win the West and the North.
However, both teams' weakness is still their defense and unless they've elevated that much on the defensive end, it's logical to predict their offense can take them far - possibly the championship game, but their defense will probably expose them at some point.
However, Dallas has made attempts (Overshown, Smith, Gilmore) to improve our already very strong defense - so it's now the strength of the team over the offense.
Eagles are a loaded team, but their weakness was clear and obvious last year. Good quarterbacks rock their stables. They played 4 good QBs all year (Dak, Rodgers, Mahomes, and Goff) and were destroyed by all 4. All you have to be is a good QB against them. Let's hope that doesn't change, so we have a chance.