The advantages of team planning

What are some of the advantages of team planning? Do you see any disadvantages that may occur, and would you wish to use this planning method in your career?
Burden and Byrd (2019) explain that “a syllabus is written statement about the content, procedures, and requirements of a particular course”, beyond that definition, what do you think is needed for a syllabus for it be effective for your planning process as a teacher?