I have 6 chickens in my back yard right now and this is not a problem and hasn’t ever been a problem in the years I’ve had them.

Same experience here. They get along really well, no fighting at all.

I'm glad it works well for you. My grandpa (when he was alive) and uncle swear otherwise. Might be because they have significantly more chickens than that.

Does the dominant rooster not cause the hens similar stress for some reason?

In our experience, hens sometimes get into squabbles and the rooster is often the one who breaks up the fight. More like a peace keeper.

Are we still talking about rooster and hens? Reminds me of work enviroment.

I guess it happens less if you don't have that many. The rare time it happened were a perfect occasion to cook "Poule au pot'

Sometimes a hen will actually transition into a rooster, with spurs, rooster coloration of the feathers, humping of other hen, calling other hens when a treat is found, etc.

The value of a rooster from me experience is protection. Last week I went out to close up the coop and found blood all over the place. Turns out my poor rooster (Cluck Norris, natch) was covered in blood and had clearly been in a tussle defending the hens from a predator. Perhaps a cat or a bird of prey. He is totally fine now and I am quite thankful that he was there.

Yeah, we get fox, opossums and weasels here. The roosters do a good job of fussing their day up.

For the opossums, it's a stand off, the rooster just acts tough and makes a lot of noise so you can hopefully show up and scare it off. Weasels are annoying as they'll destroy eggs. Fox are particularly problematic though. They'll easily kill a rooster and are very quiet and conniving.