I didn't realize this, but Addison, Jefferson, and Butler all have opt-out clauses in their contracts which essentially makes them all 1-year deals and all have bonuses due on 3/21. I feel like given the cap situation this year, we'll know in a few weeks what the future holds for those gentlemen as opposed to June 1st.
John Brown release opens up the most cash, but I'm holding out hope they restructure Brown rather than cutting him and opening up another hole.
That said, Bills could replace two players (Brown/McKenzie) with one player (Curtis Samuel - Carolina).