If the Eagles were good from 2000-2004, why are you doing research from 2002-2005? If you're trying to make the case that the Eagles won the division when their opponents were "great", why use the wrong time frame to do it?
To be plain, it's only been in 2005 that the level of competition in the NFC East was to the caliber of the mid 1980s and 1990s. Won/loss records aren't enough to ferret the quality issues out. Washington had severe issues on offense, and a revolving door at the coaching position; Dallas had been depleted of talent. New York has had a variety of issues, though the talent level in New York has been higher than the other clubs.
The one year the clubs collectively became good (2005) also happened to be the year that the Eagles lost two DTs, lost their QB in the middle of the season, lost their best RB due to injury, etc. etc.
If the Eagles recover their aggressive swarming defense, they'll be a competitive team. Then the question will be whether a team without a focus on the running game can win in the NFC East.