I agree with Peter - for some reason, the ones that come from E. Africa do pretty well, but the ones from other regions have a dismal record. One problem is that as this wide descrepency in relative hardiness becomes more well-known, you start seeing a lot more cleaner wrasse labelled as "African"(grin). I always confirm the source by seeing if the dealer has other African fishes at the same time - Chrysurus and acanthops angels, allardi clownfish and radiant wrasses come to mind.
Jay