I would have to disagree with him I have had chickens for 7 years and I have 50 chickens and about 13 breeds excluding hybrids lets see I have barred rocks, light brahmas, white rocks, buff orps,white leghorns, black giants, black buff and partridge cochins, Americanas, white sultans, mottled houdans, buff silkie, rhode island reds, black rose comb but I also have these birds spread out into 4 flocks so yes birds of different breeds will be fine living together.