Since when has Arrington been such a bad guy in the lockerroom? His teammates loved him in Washington. Watch a game some time, they all gravitate towards him.
He played for two defenseive coaches before he had his contract situation in Washington ... Shotty, who called coaching him one of the highlights of his career. And Marvin Lewis, who is currently wooing him to come back to play for him. Yeah, sounds like a real nightmare to coach.
If the Cowboys had any contact at all with Peterson coming here, there's probably no doubt that they've also had talks to the Postons about Arrington. And personally I think the "We'll never bring in a Poston's client as long as Bill is here" talk to be a bunch of hooey. Why does Parcells care about who a player's agent is? Parcells doesn't have to negotiate a contract with them like he did with the Jets, Stephen Jones does. All Parcells has to do is coach the player. If Parcells was actively involved in contract negotations I don't think he'd be in Florida watching spring training games.