Eh, the media is vastly underestimating how important Murray was to that team. The offense is going to take a step back (as much as everyone wants to give the O-Line all the credit, we can all agree that the RB situation in Dallas is worse this year), and the D was never that great to begin with (Murray hid a lot of their flaws by simply not letting the D take the field. DAL led the league in ToP last season, that's just not going to happen again this year), but now they lose Scandrick too? We'll see I guess, but DAL is in for an average season IMO.
I don't really care what opinion the media has, it means nothing to me.
The running game was important, and Randle reads zone stretches (foundation of Dallas' offense) just as well Murray. Garrett has the pieces needed to carry out his Coryell influenced scheme, the least important of those pieces is RB.
The biggest weakness of Dallas' defense was pass rush, which was addressed this off-season. Dallas' leading pass rusher from last year is at best 3rd in the rotation. They have versatile ends that can play the 3 or shade 0, weak or strong, and be effective. The defensive line rotation is the best since the scheme change.
Scandrick is a huge loss, but it is mitigated by improved depth and an improved pass rush. The talent on the defense is improved and doesn't need to be protected.
I don't think they will have a better record than last year since they face some pretty good teams and I think the AFC East has some of the best defenses in the league. But they are a better team from last year.