Disagree. Boldin could have been renegotiated to reduce his 2013 cap hit. You mentioned Huff & McClain. These are run-of the-mill guys whose acquisition doesn't come close adding talent to the team to offset the loss of Boldin. Dumervil was a good pick, offsetting Kruger's loss for less money, so I don't see his entering the discussion.
The biggest problem with using Boldin's cap space to lure a couple of average defensive guys is that we're losing our top WR without a decent backup in place. Doss & the Three Stooges behind him are below average for NFL WRs.