I have a setup with a windows desktop and a linux laptop with both an annex repository, interconnected via a backup repository in the middle (connected via ssh). Both computers are setup as clients and all 3 machines are running the assistant.
Today i tried creating an archive folder and a putting some files in it. To my understanding those files should have been dropped in the 2 machines but kept on the server.. instead I have them copied on each machine. Listing where the files are on both computers shows that both know that themselves and the server have a copy, but they don't know anything about each other.
AFAIK it looks like the bug reported in https://git-annex.branchable.com/forum/question_about_assistant_and_47archive47/
laptop: git-annex version: 5.20151116+gitg5416a1a-1~ndall+1
server: git-annex version: 5.20151109-g08bb3b1
windows: the latest build on the website
How many copies have you configured git-annex to keep of each file?
If it's 1 copy, the clients should be able to contact the server, see that it has the file, and drop it as it's in the achive folder. But if 2 copies are needed, neither client can verify that the other client has a copy, so both will hold onto their own copy for safety.