The problem that I've seen is that they learn the pecking order....until a little kid comes over. Then it isn't so pretty....
I found this to be true with sad results early last month.
My parents came down to visit us from Toronto. They'd never been to our new place and just bought 5 acres or so of their own and wanted a feel for what it takes to tend acreage when they eventually build on theirs.
My practical mom and soft-hearted father and my family were all out in the back looking at trees and the geese and ducks and chickens when I heard my 2 year old daughter start to cry. A big barred rock rooster was jumping at her with his spurs in bleep fighting fashion.
Having none of that I chased it up into the coop, smacked it in the head with a wooden stake, grabbed it by the neck and spun. Aggressive animals will not be in my yard.
I came out holding it by the neck and said something smart like, "I feel like chicken tonight". My soft-hearted father couldn't decide whether to faint or be ill. He's very into the Buddhist mindset of live and let live.
So, I had to have a half-hour long discussion with him about what living with livestock means and all was good in the end, but I don't think they will keep any roosters when they finally move onto their new property. Maybe a hen or two, but no roos.