You can keep them all. The peacocks are not so hard on peahens like roosters can be with hens.
Roosters very often just chase and grab a hen against her will.
A peacock has to fan his tail, and hope a peahen will come close enough for him to flirt with and eventually let out a special "mating call" while running at her.. if she accepts, she squats and breeding happens. If she does not accept or just is not in the mood at that moment, she refuses by walking or running to stay out of his reach and he stops after several feet and resumes the normal fanning behaviors. That's it... No problem, especially if they are free range. I had a large roomy pen with 5 peacocks and one peahen for couple years, she stayed in perfect condition the whole time. I would not even think of trying this ratio with chickens or ducks...
You can get more peahens, they will like that for sure(as adults)... peacocks LOVE to have something to shake their tail at.
One concern would be one of the boys turning out to be intolerant of other males or two of them may just not get along at all but normally, groups raised together will make and maintain a more or less stable pecking order amongst themselves.
