I have a tomato and a clarkii in my 125. The tomato is the dominant female and the clarkii is submissive. Occasionally she beats him up, but not too bad. When I added the clarkii to the 55 years back the tomato harassed him for about a month. Once the clarkii learned his place, they began to coexist. It can be done. A clarkii may not bother a perc as much, being they do not resemble eachother much.