Pretty much. Small-time chicken owner here. The best ratio of hens to roosters is about 10-to-1. Each rooster will have his "harem" of hens that keep him busy, and the hens will be content. Any more roosters than that and they'll fight a lot, and the roosters that don't have their own group of hens will hang around the others looking for a chance to rape them while their regular rooster is occupied or too far away. It can be pretty hard on the hens.

I've never had a rooster kill hens, though. Each other, sure, but not the hens. I don't really buy that.

Some context for this article that most people don't know: there are chicken breeds for meat (Cornish Cross, mostly) and breeds for eggs. The egg breeds are skinny and won't become a good meat bird no matter how much you feed them. I guess you can caponize them and they'll gain more weight, but that's a process that costs money. You could use them for soup, but that probably wouldn't be cost-effective either, so that's why the large-scale operations just kill them.