We have a Cinnamon Clown (about 3inches), Clarkii Clown (about 3 inches) and a False Perc (1.5-2inches) in the same tank without any problems.
In fact the Nemo and Clarkii share the same very large toadstool leather (12-14inches across)
The Cinnamon found a cave he hangs out in.
Of course I have a 250 gallon tank with lots of places to hide, so maybe that is why I am having good luck.