Upon doing some research (looking into Samba and the SMB protocol implementations) I've found that SMB2 and Samba 4.10+ use the FSCTL_SRV_COPYCHUNK message to offload copy requests to the server(remote machine) where possible, eliminating the need for a network round-trip.

This used to not be the case prior to Samba 4.10 and SMB2 (assumedly)

cc @bobstechsite @geniusmusing @rick_777 @rowens