Seattle is 5 & 1, so let's start there.
Review the stats and a few things leap out at you.
Except for some really sick numbers (both vs. the run and rushing the passer) by all three DL starters (Clemons, Mebane and Bryant) their PFF numbers aren't all that exceptional.
Yet when you look at more traditional stats, you learn that:
Wilson ran about half the carries as Lynch last week and is, in fact, Seattle's #2 ballcarrier.
Their run-pass ratio is 50-50. They've outgained their opponents by 50% in running yards and by a wide margin in passing yards.
They've scored twice as many TD's as their opponents and enjoy nearly as much of an edge in FG's attempted and made. No FG attempts were from outside the 50.
They have a +7 turnover ratio.
Tate is averaging about 11.3 yards per punt return. Seattle opponents are averaging just 1.2.
In short, as a team, Seattle has outperformed its PFF statistics for individual players. Why? Possible reasons; (1) Wilson's scrambling success extends drives. (2) Lynch is so good he makes his blockers look good. (3) Seattle has few if any weaknesses across the board (i.e. there are few if any holes for opponents to exploit).
How to beat them? Play hard, cut down on mistakes, stop Lynch, contain Wilson. And pray.