If Dallas is 1-0 against Seattle and the Eagles and Giants are both 0-1 against Seattle, that would make a big difference in common-opponents tiebreaking.
It's a little weird, but if it comes down to common opponents, our win against the Saints hurts us.
To get to common opponents, we would have to have the same overall record as the Eagles, to have split our head-to-head games, and have equal records in the division.
The only non-common opponents we will have are the NFC South and NFC North games. That's the Saints and Bears for us and the Panthers and Packers for them.
The only way to win the common opponent tiebreaker is to have a worse record against non-common opponents. We're already 1-0 against non-common opponents (the Eagles are 0-0).
If we beat the Bears, we cannot win the common opponent tiebreaker against the Eagles no matter what.
Of course, I'd rather beat everybody and not have to deal with tiebreakers at all.