Yes! 1 male and 2-3 females is great! The male will be displaying using his 'flash' and will be more colorful in general. I've always wanted to do this but haven't had the opportunity, yet. The females won't turn into a male as long as there is a male. If the male dies, the largest female will turn into a male. You could get a group of females, but it'd take a while for the largest one to turn into a male.
*Correct me if I'm wrong, I just dug the info about wrasses and their hermaphroditicness up from the back alleyway of my memory