I have all mine together. But, I bought my guineas the same day as the chicks. I kept them separated til the guineas got bigger, and then integrated them. They think they are chickens, and they roost with them, freerange with them, etc. The young roosters have learned not to challenge the guineas, though!
They will lose! The guineas (I have 3) stick together but mingle with the chickens. They only get aggressive when getting a special treat, or if one of the young roos challenges the younger guinea. They really stick together!
I love them!
Shelly

I love them!
Shelly