They should be able to hire ECE graduates to teach kindergarten or librarians to run the school library. They should be able to determine the optimum mix of class size, number of staff, and hours of teaching time, given their budget. And so on. Teachers, for their part, should have the right to choose their methods and materials, including textbooks, as coordinated among grades by the principal. They should, for example, have the authority to enforce the school's code of behaviour, with the full backing of the principal and school council.
Central planning works no better in schools than it does in the economy.
The difficulties and opportunities facing each student, each parents, each teacher, and each school are shaped by individual circumstance that can never be fully communicated to, let alone fully understood by, those charged with 'planning' a system of hundreds of schools and thousands of students. Centralized and bureaucratized education means that the system will inevitably be planned to suit the needs of the planners, because they simply cannot know enough about the circumstances and needs of those the schools are supposed to serve. All authority should be decentralized as much as possible.