It is helpful to have several (small) glossaries within one course, and also to aggregate them into one within the course, or even into a global one.
But it would be helpful to just put a reverence from the global one to the main (or secundary) ones of different courses. This way we avoid the update issue and don´t copy resources. A "publish-button" like for the question categories would do it.
Or do you have any other idea to achieve this?