I thought I’d share this as I had to write it up for a customer of ours recently and it’s not something a lot of people dig into, plus it’s under-documented (I had to learn off an obscure gist that roughly outlines a few steps, and nobody should have to do that). This can theoretically be completely automated fairly easily (and knowing this community, already has been), but here’s the old fashioned way to merge course exports by hand.
Feedback welcome, it’s a mammoth doc with not the clearest steps, so anything to make it easier is welcome. You can of course merge courses in this way selectively - not merging the grading policies, only merging certain parts of the content, etc., but hopefully this helps to serve as a jumping off point for getting that done and understanding the structure.