Do you have any specific concerns or did you just read something like "If you don't follow this specific ratio civilization as we know it will cease to exist" without any specifics. As Dobie mentioned the ratios you might see are based on what hatcheries use for fertility when they use a certain management method, but almost everyone quotes a 10 to 1 ratio. The hatcheries don't do that. They may start with a 10 to 1 ratio for full-sized fowl flocks but they monitor fertility and may add or subtract some roosters based on what fertility they see. For bantams they may start at 12 to 1 or even 15 to one and adjust as necessary. It just depends on what fertility they see.
Those ratios have nothing to do with roosters fighting if you have multiple roosters. They will fight over 25 hens as fast as they will over one. You can find barebacked hens or over-mated hens with one rooster and 25 hens or if you only have one hen, or they may all be fine. I'm a strong believer in trusting what you see and basing your decisions on what you see instead of trusting some magical ratio. That way it is based a lot more on reality.
When they go through puberty things can get really rough, but once they mature they tend to settle down into a calm flock. If you are having problems adding more girls usually won't solve them, it just means you have to go through an integration process on top of everything else that is going on. If you want more girls get them but don't expect them to solve any problems.
My normal flock is one rooster and between 6 to 8 hens. I've had more problems with the 8 than I have had with 6. To me it depends on the individuals a lot more than the ratio.
