The biggest benefit I see of using Commons is the "Update" feature. I personally teach a wide variety of courses and do copy some content from course to course. However, some content applies to all courses. I, therefore, like to use Commons for those Modules: Support & Services, Course Overview, Academic Integrity, and of course Canvas & Technology. This way, at the start of the term, if these documents change, I can change them once rather than in all sections.
If content is going to be developed once and not change, or your faculty wants to personalize it once copied over, then a direct copy makes more sense.
There is also the Sharing is Caring portion of the discussion. Other faculty might benefit from what you have put on Commons!
Hope my insight is helpful!
Laura