The Matthews - Symonds swap was a bit baffling at the time. More so now with the benefit of hindsight. Symonds has been playing regularly and well for Quins. Matthews has barely played for us, and only ever out of necessity. Given his experience he must've been signed with a view to him being firmly in the first team mix and rotating with JL, JG etc, but that just hasn't happened. Can't imagine their respective salaries were vastly different, so on the face of it, it doesn't look like a cap management* decision.
[* For the benefit of any Sarries fans reading, this is where a DoR has to make the very difficult decision to dispense with a player they would very much like to keep and replace them with someone with lower salary expectations in order to ensure that the club's overall spend on senior players' salaries remains within the league's agreed salary cap.]