Yeah, the red VT has never been nipped and it was obvious since the beginning that she is the alpha, and I haven't noticed either of the CT's ever having nipped fins.
Right now there are 6 girls in a 55 gallon tank. I had 7 but had to remove one because she got picked on real bad.
I also have 6 neon tetras (I had 9 but 3 of them disappeared at the same time), 6 zebra danios, 5 julii cories, 3 otos, 3 amano shrimp. I'm planning on getting maybe 12 purple passion danios at some point.