Their edge tandem is as scary as it gets, their DTs not so much. Rankins is an old-timer vet who's an OK starter but not a difference maker, kind of a Kenny Clark type. And I don't even know who their second DT is... a look at ESPN's depth chart makes it look like a JAG crew.
Anyway, Dallas bullied Houston in the run game (which was a lot more effective than the YPC box score shows), and held up well enough against the pass to get the win. You're not gonna stop both of their DEs, but they slowed them down enough.