Regal Tang + Other tang??

[Aquattro]

I have a Regal, a Naso, 2 Yellows and a Powder Blue. The Regal is by far the most aggressive. The Naso won't look at any other tang. The PB is new and smaller, but not taking a lot of crap.
Both the Achilles and PB can be difficult, so ideally have one held at the store until you're sure it's eating well and keeping weight on.