That's... Not too bad, actually. My grandmothers used to have maybe 8 chickens and 12 ducks or so. They were very low maintenance, and had very minimal pastures, with the only difficult to reproduce part of the process being that the houses were in fairly wild surroundings.
They would probably need more pasture in monoculture hellholes that have cornfields for 100km in each direction.
Yeah, the real question is whether they can forage enough food in this kind of scenario. Without supplementary grain, they are going to need a whole lot of insects to grow that quickly...
Well, no, they won't be able to forage enough if it's a small pasture. They do need extra feed.
I'm guessing that the more you do to get them forage the better the meat and eggs will be, for instance larger pasture and making sure your other animals leave plenty of dung around.
They would probably need more pasture in monoculture hellholes that have cornfields for 100km in each direction.