I have done some work with the Atlantic Longnose. Behaves similar to the normal longnose. I recommend only 1 per tank. I have been able to pair 2 up but they were raised from little 1.5” baby’s. Most of the time, they won’t tolerate each other. They do have a taste for any kind of worms (feather dusters, spaghetti worms, even had a few eat bristle worms) LPS at times, and Anemones. Most of the time they are okay. All have been great community fish but need to be watched because of their nipping habits.
I have only been able to get my hands on a few Tahitian Butterflies as they aren’t very popular in the trade. On the plus side I have been able to pair these fish up, on the down side, every one I had ate softy Polyps. Anything from shrooms, leather Polyps, and Kenya tree Polyps. They also love aptasia if you have that problem. In comparison to the Klein’s, it ships a little poorer than the Klein’s but once established its less of a risk IME than the Klein’s.
Hope this helps, Zack