I have a mixed flock of 30 birds. Before I add a breed I research it's temperament. I stick with breeds that are docile and gentle. I know that each bird can have it's own personality regardless of the breed but some breeds are simply more aggressive than others. I read reviews of a breed I am interested in from real people with real experiences - I do not go by the reviews on hatchery websites. I try to always have at least 2 of any given breed so they have a buddy to hang with. And yes, birds of a feather really do flock together. When doing my nightly head count, the breeds seem to pair up and roost together. Strange how they can tell who is who. When I see my GLW, you can be sure my other GLW is near by. When I go out to check on everyone (mine free range on 20 acres), once I spot one of my 4 Australorps, I can be sure the other 3 are not far away. Have no idea why that is. I have had a few "stinkers" that had to be rehomed becasue they just could not get along with everyone. It happens. My advise - have a mixed flock. The variety is fun and makes giving them names easier! Surprisingly, my Speckeled Sussex are mid to high in the pecking order even though they are supposed to be very gentle and low in the order. Just be smart about which breeds you choose. Flighty, nervous breeds do not mingle well with gentle docile breeds - unless they are plenty of free range room.