Well, for what it's worth, my boy was weaned in a room full of different breeds. They were all different ages. This may be because they were all socialized in this manner during their weaning stage. The Macaw and Congos were in the same room just not out with the babies. They all had separate cages, and were let out in shifts. I think if you introduce them slowly, you would be fine, but be sure to keep an eye on the Macaw, being much larger, and very playful!
Just wanted to give you my opinion.
Good luck!