I would assume you would use one of them not both. The courses of Invent Theme is one custom post type while the learndash one is another. If you are going to create an LMS, I would urge you to use LearnDash courses and related custom post types of LearnDash like lessons, topics, quizzes etc. and if you are just capturing the courses for a college/school without LMS functions, you may use the theme ones. The two, again, are not linked to each other and we don’t plans to do so either. Hope this makes sense.