The only issue I ever had with my assesors was when Scott Fellman, gave me his Peppermint Hog fish. We added it to my tank and in less than 3 seconds it swam over to a yellow assesor and bit the head off. And then 10 seconds after that it swam over to another assesor bit it in the middle, slammed it into a rock and tore the fish in 1/2.
These are great community tank fish, and if you can afford getting multiples you will definitely enjoy them.
Dave B