I added a percula and a occeleris (mispelled). They were both labeled as occelerris at my lfs
, i found out one was a true perc and took the O back... They both did get along great too..
Afterwords i found a Small true perc and added him in my 55 along with my established one. They both get along, swim together and the bigger one shows dominance now and then but after 6+ months they are both ok.
I dont know if im lucky tho..
Just make sure one clown is SMALLER. I think it will work for you.