I have recently looked into these myself.
I am only using git. I’m not a proficient user of git, only have been looking around in this particular area of usage yet. I am also looking for functionality to cross-link vault content.
What I want to avoid is having duplicates of files. Dupes would render linking for me useless. Therefore I am more in favour of symbolic links than junctions.
You can install git with symlink support and you can also add to the config files whether support for symlinks is needed or not. Symlinks need admin rights and/or developer mode turned on (one way to elevate rights; actually, apparently, enabling developer mode removes the restriction of being an administrator).
Currently, I’m only using Obsidian URI links and click the links to open the other vaults at the note referenced.
So basically I’m here to brainstorm or am “gathering confidence” to make the jump into using symlinks, possibly even with a view to using nested vaults.