I do think the Kings will schedule workouts with Wright and Green some other time, that's not the issue. The issue is seeing prospects who are "afraid" to go head to head with other equally talented players. I believe there's a reason why GP scheduled those four players at the same workout - he wants to see how well Wright and Green create offensively against a good defender like Brewer.
http://forums.warriorsworld.net/main/msgs/1548416.phtml (and a number of other places online)
Green apparently had restrictions from Georgetown, as BMiller52 noticed.