If both teams go 1-1 then Dallas will have the better division record, 5-1. Philly's record would be 4-2.
Eagles has to beat Dallas and either win week 17 or a Cowboys loss.
As for your question, Common games and then Conference games.
- Head-to-head (best won-lost-tied percentage in games between the clubs).
- Best won-lost-tied percentage in games played within the division.
- Best won-lost-tied percentage in common games (games played against the same opponents).
- Best won-lost-tied percentage in games played within the conference.
- Strength of victory (the combined won-lost-tied percentage of all the teams that a club has defeated).
- Strength of schedule (the combined won-lost-tied percentage of all the teams that a club has played against).
- Best combined ranking among conference teams in points scored and points allowed.
- Best combined ranking among all teams in points scored and points allowed.
- Best net points in common games.
- Best net points in all games.
- Best net touchdowns in all games.