You have to be certain that these players will be able to perform at a high level 3 years from now. The risk is there with any restructure like this but I think the risk is low with these players.
The cap should also rise. With an Allen contract drafting becomes even more important because you will depend on draft picks to perform immediately on good teams.
John Brown, Lee Smith, and 1 of Butler/Jefferson are likely cuts. After that I'm not sure. Beane could easily rebuild the DL next year and release Addison, Butler, and Jefferson.