Does sync playlists adds existing tracks?

[aghaken]

How does MMA actually work? I'm a new user and am trying to understand what happens when I sync playlists to my Galaxy S3. If I have songs in more than one playlist are there actually multiple copies of the song on my sd card? Or does it work like itunes? I set up auto-sync to sync only some playlists, but it looks like MM is trying to re-scan and upload the entire library. I have a 64GB card in my phone. I am syncing about 60 gig of playlists. MM is telling me there's not enough space.
I aded songs from one playlist to a different playlist and after I synced it the playlist on the S3 was empty!
And where is the user manual? The on line documentation is pathetic. No step by step instructions?
This should not be this complicated. (I started with a Tandy TRS and Compu-Serv, it's not like I don't know my way around.)

[Lowlander]

MMW only syncs 1 copy of a file even if it is on multiple Playlists selected to sync.