Everybody's experience is different, that's what is so great about a forum, you get lots of different opinions. Guineas and chicks can be raised together for a few weeks, but then the chicks get too big and the guineas get squished. As adults, the guineas WILL kill your chickens especially if they are caged. They will still attack and aggravate the chickens if free reanged but not as bad. I've had guineas kill chickens as adults and chicks kill keets as one month olds. The chicks especially like to eat the skin off the back of the keets head and neck because they have no feathers. I have gone out and found nothing left of the keets head and neck but a couple of ligaments covered in blood. So do as you wish, but I would not suggest keeping them together.