My 6inch butti was the tinyest guy in my tank probably at 1inch while all the devils and flowers were already at 4-6 inches and he pretty much out grew every body and killed everybody hes out grown and some that are bigger.
hes put down: mayan, red terror, 3 gts a 1 of my red devils and like three flowerhorns, he also used to beat on my gold flowerhorn but i moved him out before it was to late. he beat on my male dempsey and killed it that was meybe 9 inches, and he always nearly kills my smaller jag but then the jag find a hiding spot the butti can get to. these fish were all pretty fast swimmers to keep away, some even fought back. tlike the devil he killed, it fought back and the butti lost a couple times but it seemed like every time he lost 30 mins later hed go scrap again and eventually the devil gave up got chased and was killed. the buttis have a big will to be dominant.