The bottom line is that Arrington is a free-lancer and the coaching staff for the Cowboys, Commanders and Giants are all deep believers in a system scheme where players have specific responsibilities and are expected to carry them out. If he thought Gibbs/Williams was tough on him, I would love to see how he would react playing for Coughlin or Parcells.
His best bet is to find a team with an offensive-minded coach who will allow him to freelance on defense. Arrington is a decent linebacker but his freelance tendencies make it easy to gameplan around him.