When adding sources from FamilySearch it is easy to get lost in them and not remember which ones you have already downloaded. Especially when there are umpteen tax assessments or military records. I have not found a way to sort this list and it’s completely random.
Can the records that have already been downloaded not be highlighted and sorted like the Share Data screen?
Probably need more of a description on what you are looking for. The Share Data tab has very different fields and is sorted very differently that sources.
When you select something you want to “sync” on the share data page, it clearly shows you what all you have synced or not by simply highlighting the background. But the Sources page has nothing like that. If say I’m trying to sync 50 military sources, I get lost and can’t remmeber easily to know which I have already synced. And RM doesnt notify you if you select a duplicate source. Nor does it sort by date/abc/etc. Not sure the sort order.
FamilySearch concept of sources is vastly different than RM. There really isn’t anyway for them to see each other as matches so they line up. They are sorted alphabetically on each side, so that should help in determining which ones you have. From your screen shot I can see alphabetically you are missing sources 2 & 3 on the FamilySearch side. You could edit the source titles on either side temporarily if that helps you keep track.