I added an ocellaris to my tank to pair up with the other and they took to eachother right away, they did their little sex dance and now are like to peas in a pod.
I had a clarki in my fish only tank and it was picking on my goby so I put him in my friedns 125 gallon tank with damsels, a tang, and eel, trigger, and another clarki.
To tell you the truth I thought he would be beat up but after 2 weeks he paired up with the larger female clown in the tank and and fends for himself, hes a tought little bastard, the larger female clown beat up on him a little but now they get along.