If you read enough into these threads, you will hear a lot about "biosecurity." As a medical professional, what this boils down to is using universal precautions when taking care of different poultry. I think this comes about when new ones are introduced to isolated birds. You don't really know how they were kept, treated, vaccinated, etc, so keep them isolated for awhile to make sure yours are safe. I keep quail in the run with my chickens, but they are in a cage. Most of my chickens have been separated from other flocks for months (years probably) so they probably don't harbor any carrier problems (blackhead for one). Most people will tell you don't mix. My suggestion is be cautious for both a physical and medical reason. Birds are usually territorial, and don't like new neighbors, even if its the same species. I would keep them away from each other for at least a couple of weeks, then introduce them in a "neutral" ground to see how they act before penning them up. That I speak from experience. The coons killed all but one of my pheasants. I put the last one with the chickens and they decided it was fourth meal. Wasn't too happy when I checked on them in the am.
Turkeys in the wild like to roost in the trees, so they will like to roost up higher. It's impressive to see them going in for the night 10 feet up!
I'd suggest getting another turkey if you can't keep them together. They are social animals and hate being alone. When I let the children play with the chicks (chickens and poults) I bring at least two so they won't go nuts just from that small amount of time!