Just offering my opinion and support to the threadstarter, apologies to those who may have read this before. I know it's long, lol... But there's many points to cover. Basically, the reasons why I think it's fine to have a lot of roosters per hen, as long as certain quality control standards are in place.
Since they've grown up together there's a good chance they will cope, and my experience has not indicated that there is any guarantee roosters will fight over less than 10 hens each just because there are less hens, it's got more to do with the rooster's attitudes. Also if you have a flock of hens who all bunch together and your boy's personalities clash they won't share too well. Hens also tend to break up into separate mini flocks which will likely happen in your case and settle your boys down if they were left out. The majority of my boys are happy with a minimum of one hen; they would prefer around five, but don't squabble over them. Even in single rooster flocks of many hens there is always a favorite hen, lol! No breed or gender inherently equals vicious, either, it is the individual and the strain. Even in the wild, there are social mechanisms they employ to avoid the majority of violent confrontations or lessen the duration and severity of them. If they're instinctually and mentally normal, that is. A lot of modern chooks aren't, due to our breeding programs and environments.
I think that contrary to popular belief the absolute minimum hen number to keep a rooster happy is 1. Anything more is just a bonus. In the wild as well as in more naturally raised domestic flocks roosters do not want more than an average of three (or less) hens each because they cannot look after them all well enough, since a rooster's job is more than merely insemination; it's protection from predators, feed finding, and fatherhood duties when the bubs arrive that he's worked so hard to feed the hens up for. The more instincts you breed out of a bloodline by artificial/unnatural rearing and keeping increases a rooster's likelihood of being a violent sperm donor and nothing more, except food for humans. A truly good rooster has much more than that to offer. In my experience having less hens per rooster means the boys work harder to show they are good providers and fathers rather than fighting, since the hens always have enough roosters around to choose the ones that treat them best. Given a chance, they will choose rather than accepting any male available, and this is good because most animals have an instinct for their best genetic match.
This would be affected by my careful vetting for mentality type in the roosters though, but I do bring in outside roosters all the time even from one rooster homes, etc and rarely have to cull them for behavioural issues, it's like they just see how the status quo is and fit in. I often run up to a 50:50 ratio of roosters to hens, growing many for eating, and there's chicks mixing with adults, etc. I never have 'overmated' or stressed hens because I don't breed any male who shows disregard for a hen's wellbeing, so when my hens complain or tell a rooster they're not interested, they are let be; this attitude also breeds quite true and even controls the notorious cockerels. It helps to have many roosters around too. Manners can be and often are inherited. There is no excuse for a rooster defeathering a hen or harming her. One or two accidents may happen, but careless and disrespectful behaviour is not accidental and I don't tolerate it.
My situation means I cannot keep just one or two roosters at a time nor can I cage them all separately even if I wanted to, and under no circumstances can I tolerate violent chickens that harm eachother or people, so from the very first batch of chooks I bought and from then onwards I removed any nasty birds. In total out of hundreds of birds I have culled, the removals for bad behaviour have been very minimal. One rooster from the first batch for violence to humans, a few for excessive aggression to eachother or disrespect of hens or sexual attraction to either chicks or humans, and other than that most of the boys I've culled for food were in fact good roosters, just not a 10 out of 10 in the way some other males were, so bad luck.
If you cull out bad attitudes, supply room to roam, and a good diet, you can have a peaceful flock. Working around bad attitudes on the other hand allows them to breed on and makes you work harder.
As far as I can see, the real reasons roosters are most commonly seriously or even fatally violent to eachother is often a mix of factors including them being bred and reared in socially restrictive environments, usually from fathers who were caged in the first place due to their intolerance of other roosters, and socially unskilled chooks, like those bred for intensive production in massive hatcheries, lacking the usual understanding of how to get along and accept their places in the social order. If you separate but keep roosters because they do not get along, beware that you may just be perpetuating the intolerant attitude, which breeds pretty strongly true. I cross mixes, mongrels etc from all different families/breeds/strains and one thing that I can count on more than genetics is always attitude breeding on into offspring at a high percentage. I have a policy of removing any chook (male or female) that is excessively mean or violent and you will often see this attitude surface in young chicks if it is present.
Bah, I never seem to present a concise opinion... I try to offer my experiences as the reasoning behind my opinions and theories, and it gets long because there are always multiple factors... Anyway: my belief is that you can have healthy, friendly, peaceful and calm chickens of all ages, breeds, both genders etc ranging together if you do the following:
1) Remove any troublemaker you spot, either gender, who likes to bully. There is hierarchy reinforcement and there is nastiness and harassment. Bullies often begin as chicks and often breed that attitude on.
2) Provide a fully satisfying diet so the instinct to reduce numbers due to nutritional insufficience does not kick in. Kelp powder is my basic multivitamin and mineral source for this.
3) Allow space to roam and space to choose roosts away from birds they don't consider part of their immediate flock. This will also prevent the instinct to reduce numbers due to overcrowding from kicking in. I supply multiple cages and they pick their roosts. 'Teens' naturally tend to segregate themselves.
4) Rear chicks with their mothers, free ranging with the whole flock after a week or less, and always cull any male or female who is violent to chicks. It does wonders to a chicken's social understanding to be reared naturally as possible with those of its own gender as well as the other, and older, calm birds of both genders are a vital influence to younger chooks in learning their manners.
If you have a goal in mind for what you want for and from your flock and what your and their basic needs are, you're well on your way. I decided on some basic laws laid down that guide my flock's progress in terms of what I will not tolerate for their sakes and mine. Violence, flightiness, etc are all things I cannot have since they are directly counterproductive. You need to have the setup (space and diet) and supervise enough to spot the troublemakers, if you want to do it the way I did. Totally worth it in my opinion but it's not for everyone. Best wishes.
