2 tangs in a 90?

[vertigo01]

My 2 may be the exception and not the rule. I have a Blue Hippo around 5" and a sail fin roughly 6 1/2" in a 48x30x30 ( 180 Gal ) reef tank.
Maybe they are the exception and not the rule, but they are more like best buddies as opposed to enemies. They are always together and I have never seen them fight.
Could it possibly due to their shape as well as coloration, that they get along so well?

 

[Sk8r]

Possibly due to their level of maturity. Fish have a way of hitting a 'point' which makes no particular sense, but apparently somebody gets ticked and it goes south from there. In my gradschool days, I walked into the National Aquarium (which at the time was in the basement of the Commerce Building)---and the piranha tank was like fish stew--pieces of large fish floating everywhere. The keepers were at a loss, trying to figure why fish who had lived together for years suddenly went bozo and left only a couple of survivors. LFS had a rabbit suddenly, after years, decide hammer coral looked delicious. Our 'little' tanks are a kind of stress in themselves. Best not to make them more so.