I am new to chickens and have purchased 2 Leghorns and 4 Amercaunas. They are 12 weeks old. I would like to add 6-8 more and I am trying to decided what I want to add. My thoughts are Barred Rock, RIR and maybe Wyandottes. Can I safely mix these breeds? Are some breeds better than others to mix? I am mainly into layers as I am trying to add chickens to my farm business. Thoughts? Advice? Just so you know my henhouse is 4X8 with 6 nesting boxes and they have a large fenced area to run in and I have been letting them out in the early evening for a couple hours to forage. TIA!