David, I have had Muscovy ducks, turkeys and chickens all together during the day. The turkeys had their own house because turkeys insist on heading to bed at least an hour before sundown. If I didn't lock them in, they would fly up to the roof of the coops. My henhouses are the boxstalls from our horses (when we had them). The roofs are probably no less than 15 feet tall on the tall end. The turkeys would want to go up there, rain or shine and then they would call and call and call. Now if one ever has heard a turkey that thinks it is in peril, their voice can be heard far and wide, they are loud, and it is something that cannot be ignored. So. They had their own house. We have lots of rain here and allowing the birds to naturally roost outside is not an option. I don't have the turkeys anymore, they were too much work for the set up that I have. When we move and I am set up better for turkeys, where they can't roost on their house, I will get more. They are a delightful bird, that will keep you watching and looking at them, I loved my turkeys, they went to a woman who was in love with them, and they are well taken care of.
I have also heard of blackhead that turkeys can get from a parasite that chickens can live with, but it affects turkeys. My turkeys never got that thing, they were healthy right through to the bone. I know that because we have eaten the youngsters, smiling. Heritage turkey is nothing like the commercial bird. WE had a taste test of both types, and no one wanted to finish eating the store bought one, whah.
Turkeys can be a little on the aggressive side to the other birds when they are beginning to think about laying eggs. They will single out someone and just keep walking around and around, surrounding the bird. There was never any harm done on these walkarounds, but sometimes, they just didn't like a specific bird.
Anyways, just a little experience that I have had with heritage turkeys.
I would never have guineas because the the hideous noise they make. To me, the sound is intolerable. Where we live there is alot of bush surrounding the perimeter of my property and it seems to echo noise. I couldn't have such a noisy bird here. Good luck with your endeavour. Have a most wonderful and awesome day, love life, health. Cindi