SWM desktop gets two different versions: design and contrib. Contrib just gets data view and update forms.
But most important is a "sync" feature, getting all the latest content from the server at the start, then again when publishing, to make sure you don't write over some other contrib'rs update. Only what if both contrib'rs update at the same exact second? Maybe limit concurrent FTP'rs to 1 or just take the risk (the update will still be current on the contrib'rs local machine, so the only "bug" would be they would have to hit "publish" again).