Ah, the chicken gremlin phase. We know it well. There is something beautiful about a person who decides to build a coop before they even own a single bird, calculating square footage for a flock that doesn't yet exist. This reader is doing the work, researching like a possessed farmhand, and we respect that. They've landed on two heavyweight contenders: Brahmas and Faverolles. Both are known for being calm, docile, and generally too polite to start a ruckus. That is smart thinking for a first flock.
Here is our honest take: a mix is the way to go, but not just any mix. If you throw a Brahma and a Faverolle in the same run, you get two very different flavors of "chill." The Brahma is the gentle giant, big, feathered feet, slow-moving, and about as threatening as a cloud. The Faverolle is the fluffy friend with the beard and the mellow attitude. They won't fight. They probably won't even argue about who gets the good snack first. But here's the practical thing: if your neighbor's cats are free-roaming, those big Brahmas might look like a slow-moving feast. Faverolles are smaller and quicker, but they also look like walking dust bunnies. Either way, your run needs to be Fort Knox. Build it big, build it secure, and then add a roof. Cats are persistent little hunters.
The reader mentioned they do not want roosters until they are more comfortable. Smart. A rooster is a whole different level of fowl play. Without one, your hens will be quieter, less likely to start a dawn chorus, and much easier to handle. Both breeds are known for being excellent mothers and friendly pets. You will probably get attached. You will probably name them. And yes, you will probably change your mind about productivity once you see that first perfect egg. That is the trap. You start saying "I don't care about eggs," and then you find yourself googling "how to get my Faverolle to lay in the nesting box instead of under the bush." It happens to the best of us.
So here is the concrete advice: pick three Faverolles and two Brahmas. The Faverolles will keep the energy light, and the Brahmas will keep the ground warm in winter. Both breeds are excellent for novices, and neither will judge you for chickening out on the rooster question. Just make sure your run is predator-proof, your coop has good ventilation, and you prepare yourself for the moment you realize you now own a tiny dinosaur who judges you from a perch. That is the real chicken math.