Only a little bit of chicken math.
I wanted 4 small bantams when I started keeping chickens. Because the coop I had was not big enough for normal size chickens and I thought it wouldn't be big enough for 6 (my ideal number at that time).
After the first year I had 3 hens and a rooster. The rooster was too noisy and had to go. But I waited until spring and let my broodies hatch some eggs. I made an extension to the coop and 3 pullets stayed. So I ended up with 6 hens and kept a status quo for a couple of years.
But getting older, the chickens had longer breaks in winter and I wanted to add young blood for more eggs especially during winter. I looked for a bantam breed with the right specs and bought Naine de Tournaisis fertile eggs to please my broodies and minimise the chances of getting an illness into my flock. But only one Tournaisis was laying all winter.
Because I don't want to cull my older hens I suppose I will get more and more chickens if I want to have enough eggs for us. And I like to have my own organic eggs at least 10 months a year.
Now I have 8 and there is enough space to keep them happy. I suppose they eat no more as you're 3

.
To prevent an overcrowded coop I will start adding light when they stop laying. I read that it takes about 6 weeks for chickens to start laying again after adding light. So they can have a winter break, but not too long.
And maybe I will buy fertile eggs again next spring. I am already in search for a small bantam breed that is strong, lays even in winter and is not skittish like the Tournaisis but more social like the Dutch. There is room for 2 more if the chickens can free range a couple of hours every day.