Multiple Tangs

I recently brought home a couple tangs.
Two yellow
One Brown
One Sailfin
I had them all together in a Qt. Big mistake. They were all fighting and that was in the space of a couple hours.
I however, skipped QT because they were already perfectly healthy when I got them and the drive home was only about 15 mins.
I separated them but putting the sailfin and one yellow together. They seem to be doing well together, I then placed the other yellow and the brown in another tank. They fought a bit so I'm keeping the brown separated for now. Things seem to be going well with this mixture.
So I guess the theory of similar colors and similar shape with tangs is a bad mixture is very true. Adding them at the same time didn't work out for me.

 

i keep 4 tangs i my 90 a blue hippo yellow a sailfin (the largest and king of tank) and a violet they have all been in the tank for just under 3 years with very little issue and that is when the yellow gets in the sailfins teratory.