Ygritte, for what it is worth, I grew up on a farm where the chickens not only free ranged, they took care of themselves in the good weather months. In the winter we did supplement their food. But we had absolutely great forage. All kinds of grasses and weeds, cut an d uncut, grass and weed seeds, plenty of nasty stuff for them to scratch around in (cow and horse manure, decaying vegetation mater, etc.), and all kinds of creepy crawlies for them to catch and eat. Very few people have forage of that quality so supplemental feed year around is probably necessary.
These chickens also hatched and raised their own replacements. No incubators. We did not eat a huge amount of chicken meat since we also butchered hogs and a small beef so we did not set that many eggs, we didn’t need them. We had somewhere between 20 and 30 hens at any one time, usually just with one rooster. Practically all the eggs were fertile. We did eat a huge amount of eggs.
While Dad would bring in Dominique or New Hampshire chicks every four to five years to keep up genetic diversity and to increase the physical size of his flock (bigger chickens), the backbone of that flock were game chickens. Game are not as big as the normal hatchery dual purpose chickens but they are excellent at foraging and go broody a lot, making excellent mothers. Our flock was a mutt mixture of games and some dual purpose breeds.
Your earlier post made it seem size was an important criteria for you. Maybe it is. But Mom could feed a family of 5 kids with one of those game hens, it did not have to be a male. Some of the individual pieces on the platter were back, neck, gizzard, and liver; you won’t find those in a KFC bucket. Chicken and dumplings and stews are a great way to stretch a chicken to feed more. If you are wanting to be self-sufficient maybe size isn’t your most important criteria.