Devils advocate here. If you build a dominant defense you don't have to have a "franchise" QB to win. You just have to have a competent one. One that understands the system and can run it without making big mistakes.
Schaub was more than capable of taking a team with a dominant defense and strong running game to the promised land .... until his body broke down.
Mossup is right .... Its not like Russell Wilson lit up the league this season , he just got the ball to the playmakers and didn't make many mistakes in the process. While Texans QB's made mistake after mistake .... after mistake.
What's difficult is finding a guy who can jam the receiver, then turn & run with him... or a guy who can miss on a jam & recover. Otherwise, you're going to need really good safeties with really good range to cover the deep middle & make up for poor line play by the CBs.
Right now, we need our safeties to do that & compensate for poor play of the LBs in the middle of the field.
Sure , its harder to find a guy who has size and the ability to cover and make up ground .... but when you are the only team looking for those players , it gives you a larger pool of players to choose from .... while the other 31 teams are all looking for guy's with speed and closing ability to break on balls ...
There's a difference in the type of player tho , these guy's don't have to be fast , back peddle and flip their hips for recovery like the traditional corner. They just need to disrupt and run with the receiver.
The trend in the NFL in recent years has been for the defensive backs to give ground and make a play on the ball because of the rules. The good QB's are able to exploit that by getting rid of the ball quickly. Seattle's defense takes advantage of that 5 yard chuck rule and plays them physical within that space then they remain in tight coverage. They don't need so much speed because of that tactic. Its hard for a receiver to use his speed with a defender engaging him.
Their scheme covers up a lot of inadequacies .... you jam guys at the line it disrupts the timing of an offense and buys time for the defensive front to get after guys which essentially reduces the time the defenders have to cover "In route".
We always talk about our defensive backs needing to cover until the DL can get pressure but this tactic allows the DB to buy time for the DL rather than waiting for the DL to get there. It's like cutting that time in half.
Imagine how many sacks this Texans defensive front could generated if they were afforded that extra half second rather than having the DB's play 7-8 yards off the receiver ....
Seattle's defensive concept is simple and efficient. While the rest of the league (in general) is chasing chickens , their DB's don't let the chickens start running ... they catch them at the roost.