Just wanting to add my 2 cents and my experience. I had 2 maroon, 2 tomato and 2 other clowns (can't remember the type) along with a couple damsels and a yellow tang in an 80 gallon tank. They all got along together fine, usually each type paired off and didn't bother another type. If it wasn't for my stupidity and mistakes, they would still be living in my tank. Granted, I am still learning this hobby, so take my opinion as it is, an opinion. Just wanted to let you know they were doing fine for several months (5+) before I goofed up.
I did add most of them at the same time. Maybe that helped, I don't know.
One thing I have learned from reading the posts here is that everyone has an opinion and their own experiences. And that another person has the exact opposite opinion and experience of the previous post. As such, when I upgrade to a larger tank for my tangs, I will probably put several clowns back in the 80 gallon as this worked for me and they provide lots of colors to the tank (she likes colors and clowns).
Hope this helps!