C's
Trade Sheed, Ray Allen, Sheldon
Receive Nocioni, Martin, Augustin, Law
Cats
Trade Augustin, Law, Henderson
Receive Sheed
Kings
Trade Martin, Nocioni
Receive Sheldon, R. Allen, Henderson
C's get what they need a young SG to replace Allen, a backup SF, and a backup PG. It does hurt the interior some, but it is a solid trade.
Cats get a veteran and interior help which they need for two backups and a young guy that is a minimal rotation player at the moment.
Kings save a ton of future salary and pick up a solid young SG/SF in Henderson that they can develop and a younger PF that they could probably re-sign on the cheap if they desired.
Also there are enough pieces from each of these teams that the C's in theory could make this trade and keep Ray Allen by using a number of their smaller contracts. Something like Scals, Daniels, House, Davis, and Sheed is enough to take on both Martin and Nocioni. So it can be done and keep Allen, though I'm not sure the blow to the interior depth is worth it in that situation.