Moving files directly between two Synology NASes is a level of suck I didn't want to deal with today. Cannot sort out drag-and-drop, CIFS, or SMB and have devolved to remote-mounting via SSH. So hours of SFTP between two machines less than 15 feet away from each other on the same internal network.

The whole point of having a NAS is to NOT HAVE TO BE A DEDICATED NETWORK ADMIN TO JUST TRANSFER FILES ACROSS THE GODDAMN HOUSE.