RW kills teams when he can just roll out and has open field in front of him, forcing the D to try to guess if he'll scramble for a 1st down or is just buying time to make a deep throw. If you can bottle him up in the pocket he becomes much less dangerous.
This Seahawks team really only has 1 good receiver - Lockett, who has gone completely nuclear this year out of nowhere. Take him away and the passing game is not much to worry about. Their TE is a nobody and their running backs aren't passing weapons.
The task is basically to stymie the run game, keep RW in the pocket, and cover one guy on deep routes. I'm not saying all that's easy, but the Seahawks are not going to fool you, either. They basically are what they are. They aren't a team like the Patriots who might do a complete 180 from their normal tendencies from one game to the next just to mess with you.