Fu Manchu gets a maximum of 4”, fuzzy dwarf and dwarf zebra get 7”. The fuzzy or zebra will eat the 6 line when they outgrow him, if not attempt it before. I have kept a few different lionfish over the years. My first was a Mombasa lion in a 65 gallon tank. He was full grown and in with a 6” maroon clown and a 3” Falco hawkfish. He could have easily eaten the hawk but I’m guessing he mistook it for venomous considering they both had similar colors.
I have also kept a fuzzy and a zebra together with a different maroon clown. The trick is getting the clown about 4” and the lions smaller. They grow quickly if fed properly. The maroon is a taller fish and mean. I would not attempt a pair of clowns as the male stays smaller and could easily be eaten by the lion. Wartskins will also eat things you wouldn’t believe would fit in their mouths so I would stay away from them. You may get an angler that choked to death on a lionfish.