Doc Rivers has already seen two assistant coaches leave the Los Angeles Clippers for better assistant coaching gigs elsewhere: Alvin Gentry left for the Golden State Warriors while Tyronn Lue left for the Cleveland Cavaliers. Eventually both of those two became head coaches of notable teams: Gentry with the New Orleans Pelicans and Lue with the Cleveland Cavaliers. Now Rivers and the Clippers may see Mike Woodson leave the Clippers to become a head coach outright with the Sacramento Kings.
The Clippers have given the Kings permission to interview Woodson. While it's still unclear how good Woodson's chances are for the gig in Sacramento (pretty much any warm NBA body is getting an interview), Woodson could still impress enough to perhaps go the route of Lue and Gentry and become a lead assistant coach on the Kings or somewhere else.
So while some people may complain about effectiveness and/or wisdom of Doc Rivers' (and his staff's) coaching, the rest of the NBA evidently is taking notice of the Clippers' success and happy to snag from their assembled coaching pool. One can only wonder when Sam Cassell's time will come. Alas, if the Minnesota Timberwolves were not already on the cusp on playoff contention and glory (like the ascension of the Oklahoma City Thunder), perhaps Sam would have gotten the gig in Minnesota (instead of another former Doc Rivers' assistant: Tom Thibodeau).