I never recommend a betta sorority but some people can make it work. Like stated above, LOTS of good hides and make sure each queen has enough territory to claim and reign over so they leave each other alone. Keep a close eye on them (pretty much forever) to ensure nobody is getting beat up. Bettas are so unpredictable, as far as living with each other, that you never know what you're going to get. Good luck!
Platys, Tetras, Mollies, BN Pleco, Crayfish