Arrington and Peterson have two different styles of play. I have never thought Arrington was as good as his hype and think that Peterson would fit our defense better anyway. I remember watching a 49ers game (wife is a fan) and watched Peterson cover the slot receiver and pick the pass. The thing is, this wasn't a slant or anything, he actually had to turn and run with the receiver. Granted he didn't do much of that in his career, averaging 1 pick a year, but that play stuck out in my mind. Personally between Arrington and Peterson's injuries and issues, I say pass on both unless the contract is Cowboy friendly.