Authors need learning and domain knowledge. Finding people who know both will be challenging for many universities.
One scenario is for instructional designers and faculty to work together. Another is for faculty to learn about learning, and improve their courses over time. A few regular faculty might be willing to do this. A third option is to use lecturers who do not need to publish. They would have time to learn about learning.
Instructors are responsible for helping students when they get stuck, monitoring student progress, and assigning grades. Regular faculty, adjuncts, and graduate students could fill this role. They don't need to be learning experts, since authors and Skilling's tools bake learning goodness into courses.
Graders could be casual workers hired as needed. They only need enough expertise to interpret and use grading rubrics.