His first contract as will most the others may be doable, it's the second one that I think gets tougher. Guys that have a better handle on this then myself can correct me, but Kam, Sherm, Browner can all be extended because either they are vets and not on their first contract (Browner) or are past the 2nd or 3rd round and there are a different set of rules regarding how those players are handled, not the 4 year contract that first rounders get. Most later guys are on much shorter contracts and can be extended after a shorter window I though.
With all that said we can reasonably stagger guys, Kam then Sherm. Browner becasue they are not 1st rounders. Earl will be the guy that gets into the real teeth of CBA rules.