I have my pheasants and Chukars together lol but that isnt what you asked. I think putting them with turkeys is fine because they carry and contract the same diseases, this is why you should not put pheasants with chickens. I dont know anything about guinea fowl so I will leave that to somebody else to answer. Also just so you know they will have to be separated when breeding season starts because male pheasants will get possesive and agressive towards the other male birds in the pen, even if you have had them living together for 6 months before breeding season and they are fine, breeding season brings out a totally different bird I have found.