Earlier quoted context omitted.
Regardless of how you're deploying things, having unrelated projects in the same git repository might be simpler (maybe?) but certainly seems worse at the same time. Sure, if they're actually unrelated, or being managed by separate teams then split it up. Though I think the default should be to have one, and split it when there is an actual reason to, especially if it's for the same project. The example I gave wasn't…
i'm wondering what engineering decisions drove the project to be split in 14 parts? is it like micro-services thing or what?
I think it really just came down to dividing the repos into chunks that the deployment scripts could use/trigger off of. Instead of developing in a way that makes sense for developers and bending the deployment to fit. Since it was all in one directory on his computer, it was basically a mono repo from his perspective. Committing from the IDE just committed to whichever repo was changed, and since he was the only developer he never saw the downside. When I had to take it over ghorg[0] really came in handy. It's a script to clone all repos from a user/organization on gitlab, github, and others. Then once I opened up all the repos as one pycharm project I was able to get some stuff done, but at that point I might as well just had one repo with a separate directory for each.
[0]https://github.com/gabrie30/ghorg
EDIT: I also just remembered that gitlab is much better than github if you are going to go the route of multiple repos for one project. Gitlab lets you create namespaces to group your repos, so if they're all in the same namespace, you could have documentation to just tell people to clone all of them.