It is dangerous and usually doesn't work. It takes away continuity or momentum. Teams have to play the way they got there. Look for the Bills to make the playoffs with Indy over Denver.
Why all the AW bashing? It's all about the money with most of these guys. AW is a stud leading the Vikings in Defensive tackles Special Teams Tackles Interceptions and forced fumbles. The departure worked out for both parties which is fairly unusual.