KK, the only point I see I see in your MHS principal example is that a superintendent maxes out at $150-$200K if their school district has over 1,000 employees and 5,000-7,000 students.
By comparison, Schulz started out making $350K at a university with over 24,000 students, an endowment over $350MM, and over 1,200 academic staff. Plus Schulz has to deal with at least three more major tasks in fundraising, research, and housing & dining.
The max-out of $150K-$200K for a superintendent of a district that size seems about right.