you're correct that we don't have NFL top tier receivers, but the ones we have know how to play within our system. Baldwin is an exceptional route runner who will find a way to get himself open, and Kearse while not fast is a deep threat thanks to his ability to box out the defender and get the ball. Not having Richardson is going to hurt but in comes Lockette who can turn on the speed (when he's not killing us with penalties anyways). Luke Willson can't be overlooked in the passing game either. He's big, and he's fast. He suffers from the dropsies at times, however. Lynch has also been an important part of the passing game this year as well. Obviously he's no Matt Forte.
Overall though the strength these guys have is that they've been playing with Wilson behind that shaky oline for a while now and they are accustomed to the style of play that requires them to find ways to get open, and they do so very well. Watching tape of our games you'll see these guys routinely wide open because of what Wilson brings to the table in extending plays, and just being a threat to run. So often the guy who should be covering Luke Willson will cheat up to contain RW, only to get a ball lobbed over their head to the TE.
If i were the Packers I'd almost make containing Wilson and taking away the passing game first; it seems counter intuitive, but the Seahawks either way are going to bludgeon the middle of your defense with the run game, probably using all 3 backs to do so to wear them out by the 4th quarter. I'd use Seattle's own strategy against them - run down the clock, and hope for big plays on offense while counting on your D to play strong red zone defense and force field goals.
If you sell out to stop the run, you'll get burned. Ask the Panthers how that worked out. They took our receivers lightly and made stopping lynch the focus and Wilson had a 3 TD 0 pick day against a team that's been fairly sound against the pass all year.
If the Packers want to win, they'll have to do two things well:
1.) Hold Seattle to field goals; this isn't impossible to do. Russell Wilson is VERY careful with the football, especially in the red zone (2 picks in 53 games in that area). He will throw the ball away at first sign of trouble, and the team is coached to protect the ball and get points at all costs
2.) When GB gets in FG range, get points. I know opposing teams fans don't like hearing it, and many want to discount it, but the clink is loud and it DOES affect things, to think otherwise would be silly. You try doing any activity that takes a concert of athletic constitution and mental awareness, and then drop 70k screaming lunatics on top of you and see if your performance doesn't suffer.
So many teams get inside the 40, and give up penalties or sacks and get knocked out of field goal range, inspiring the defense and feeding the crowd, and end up getting a big goose egg for their efforts. if the Packers want to win you need to come away with points when you get inside that 40 yard line. Every time.