Ok. The Saints have a 3-4 Defensive scheme and the Hawks have a 4-3. Statistics are great but its the offense vs. defense matchups that matter. You have to look at what offensive schemes vs what defenses, its not as cut and dry as looking at statistical rankings. Also, every week adjustments are made based from film and correcting mistakes. This is why the phrase "any given Sunday" exists.
Are you saying that the Seahawks match up better against a 3-4 scheme? If so, the Texans are laughing at you. How about a 4-3 scheme? The Rams are now laughing at you. This has jack shit to do with schemes and everything to do with pressure being applied, and the OL not responding to it.
And what difference does it make if the Hawks run a 4-3 and the Saints run a 3-4 scheme? The defenses do not play one another, so its a moot point.