I added a pair of Clarkiis to my 100 FOWLR 2 years ago. I already had a couple of Darwins and 1 Percula in addition to several angels and wrasses. At first, the Darwins bullied the smaller Clarkiis, in concert with the Percula. Now the Clarkiis are much larger and have turned the table, big time, to the extent that I don't expect the Darwins to survive. The Percula has switched sides and now joins the Clarkiis in attacking the Darwins, though the Perc is much smaller. I was attracted to the Clarkiis due to their charming habit of feeding larger sinking pellets to the anemones, but now very much wish I didn't have them. Everyone else seems to be getting along.