From your first post:
This setup tell sonar to ultimately look in /mnt/user/appdata/downloads/sonardrone/sonardrone (since /downloads is a shortcut to /mnt/user/appdata/downloads/sonardrone)
Same thing with Radarr.
Like @chbmb said, if you set the mapping for /downloads to the exact same mapping on every container applicable, it should all work fine. As a matter of fact, once its all set up correctly, any new downloads won't have to go through the drone factory, and the intercommunication via the API's will automatically begin the imports once they are completed. But, I don't ever use deluge. But it will work no problems with Sab/nzbget