I got a little bit impatient and released all the girls into the tank (sorry, guys).
I'm having trouble finding out what the "pecking order" is, though. It's basically just this:
1) Violet (she's much bigger than everyone else and seems to be using it to her advantage)
2) Everyone else
At first she wasn't that bad, just regularly chasing a girl, resting, then going to chase another. But she's starting to chase more now.
Also, apparently the girl that seemed like she would be 2nd most aggressive hasn't really even interacted with any of the others. Even though she flared at them whenever she saw them from inside her container. Oh, and Violet also got pretty picky about the top area when it was feeding time.