In my experience, WordPress sites are simply not friendly with version control. I cannot imagine seeing too much success with repos for content that does not match the database state at the time. If you try to checkout a past version and cannot recreate the database at that point, your site will frequently break.

The only success I've gotten is to track the entire site, uploads and all, which is quite impractical but is relatively easy to deploy, especially with hooks that save the DB in a SQL file on commit and export it on merge.

A major caveat is that due to the nature of the SQL data, you cannot merge between versions with any real freedom, if at all really, because the SQL data will differ to much and you will almost always have merge conflicts for which there will be no clear answer on satisfying both states.

Still waiting for the messiah to come along with all this. The article makes a good point about tracking only the content you are actively developing, but it is unrealistic in it having nothing to say about tracking the DB changes. Again, that's the only way you will be able to checkout any version of the site and have it still work.