My gut feeling is that we'd better sweep the Eagles. After messing around with the ESPN playoff machine, there are very realistic scenarios where we miss the playoffs at 11-5 if we split with the Eagles, and the Eagles, Lions, and 49ers/Seahawks all end up at 11-5 also. Eagles win the division if they beat Washington and the Giants, and there's a lot of ways for us to lose out on a three-way tie for the two Wild Card spots (depending on how the games unfold, we could lose a three-way tie at 11-5 with the Lions and Seahawks despite the head-to-head edge on the Seahawks. A three-way tie of Cowboys/49ers/Seahawks is the one that bodes well for us).
I think the Packers are a very good team who will probably win their division at 12-4, but the Lions could still easily go 11-5 as well, losing only to the Packers and Patriots. If the Bears can get things together somewhat, they could have a thing or two to say about the playoff race, given that they play the Lions twice and the Boys at Soldier Field.
The 49ers haven't looked as good as usual this year, but they've got Aldon back, and their schedule sets up nicely besides two games against the Seahawks, which they'll probably split. They play the Cards at home Week 17, where it's possible the Cards have the #1 seed locked.
I just think there's a lot of solid but not elite teams in the NFC, and we should sweep the Eagles (or if not, sweep every other game) if we want to make the playoffs without needing help. Missing the playoffs at 11-5 is an unusual occurrence of course, but I'd rather us control our own destiny nonetheless.