When you start yours. Make sure it is heavily planted. Fake or real plants doesn't matter and some caves. Make sure they are tall plants that will break their line of sight. This will help with agression. Since you will have a brand new tank expect little nicks and bites here and there. Thats normal. Watch them closely for to much agression like the original poster has. To much attacking, open wounds, fights that don't end quickly.... remove the wounded or the agressive. Treat the wounded of course :) You don't have to float the original ladies for a couple of days. Just acclimate them and release but watch them closely for any agression. Oh and for the original poster as well, you can try to take all the girls out and rearange the tank and re-enter. Some people have sucess with that but I have more sucess with floating them in their cups.
The best trick to reintroduce an agressive fish is to float them for a couple of days with the idea they will be sorrounded by all of the girls but won't be able to attack. The idea is that this will retrain the brain to a more relaxed states when around others. Sometimes it doesn't work. I usually try it 2 or 3 times before removing them permenantly but I have a decently docile group. Just a few nicks. The important thing in a sorority is to keep the water super clean (because of the nicks in the tails) and watch for agression. Also equally important. Later on down the road if you add more girls be sure to quarantine them for illness.