I've raised them in several different situations over the years. The most important thing to remember is that
chickens carry a fatal parasite, blackhead. The
chickens are immune and show no symptoms, and almost all
chickens with access to the outdoors are carriers. So you have to keep turkeys and chickens well separated at all times. No overlapping pastures, etc. Even so far as, if you do raise both, always do the turkey chores first, lest you track chicken manure over to the turkey area! Old heritage turkeys, especially fully grown ones, often show some resistance....thus explaining the occasional spectacle of a farmyard where they seem to coexist.
Turkeys in general are more persnickety than chickens. They need a higher protein diet when young, and seem more prone to dying off from various causes....If you get a breed that can hatch and raise their own young you might have better luck than with an incubator, etc. Modern "broad breasted" turkeys are even worse than the "meat chickens"....as far as clumsiness, etc. goes. The toms can't even perform their masculine duty effectively, so they are often artificially inseminated. Even with heritage breeds, keep the tom away from new hatchlings....walking around puffed out to impress his woman, he can't see his own feet, and winds up stepping on the chicks, often killing them!
On range, turkeys will scratch less and hunt for insects more as compared to chickens. Years ago we had some in the same pasture as a
dairy cow, and they would follow her around and pick off the horseflies. Eventually the cow learned to lie down when the flies were bad, and let the turkeys walk all over her to get at the flies!! Also the birds would scratch the cowdung completely away into the grass looking for bugs and worms in it....