Hi Ramo,
It took me a while to understand that the "Course creator" role was not that of a super teacher, but of a sub administrator. Their role is basicially just to set up courses and to allocate teachers to them.
"Course creators" are only really necessary in a large institution where the Administrator doesn't have time to set up all the courses and so delegates the work to other people: typically one "Course creator" is set up in each department. This person is not necessarily the head teacher in the department, it could be a secretary or technician. This is why "Course creators" can only intervene in the courses they set up: it wouldn't make sense for people from the maths department to modify courses in the French department and vice versa, would it?
It is the role of "Editing teachers" to create and edit the pedagogical content of a course. There can be two or more "Editing teachers" working as a team in the same course.
It's true that "Course creators" can teach in the courses they create in the same way that Administrators can teach in the courses they create but they don't usually do so. They have the capabilities just so they can sort out problems.
Cheers,
Glenys