first off the hottentots!
But yes, I have seen countless collections with E.A. Crowned Crains or Demoiselle Cranes in with their waterfowl collections. None have ever told me of any messing with their smaller birds. I wouldnt advise mixing the cranes, but from all I have seen and heard, they get along just fine with waterfowl, especially in a set up as large as the one you have.
Many years ago, a buddy of mine (a professor or Ornithology at FSU) had both in his various aviaries. He was one of the original people who got me started in all this. But that's one thing I always remembered about his collection, those long legged cranes walking around with his teal and Argentina ruddy ducks, it was a beautiful collection.
Unfortunately, the city of Tallahassee made him close his facility down years ago because he was too close to a stream and they accused him of pollution when draining his ponds.....like a metro area like Tallahassee needs to be worried about a duck keeper being their biggest polluter! what a shame.....