Top Ten is a stretch but they will be improved. Fluker is a massive run game upgrade for them and improvement from Poicic and Ifedi is natural. They will still be weak in pass protection but Russell can deal with that.
Watched their game last night and the defense was impressive. Especially the seconday. In my opinion, they are the second best team in the NFC West by a good margin. The punter and having an adequate kicker is enough for a 2-3 win improvement alone.
I would not sleep on the Seahawks.