I am guessing you have not been to too many first and second round games over the past 10 years. The disparity between the top teams and lower teams in every division is enormous. You can argue that the top teams can just play all their reserves but the reserves will beat these teams by 15 goals if allowed. It is simply not fun for either team.Please, please NO. An open tournament is a much better format. The Divisions 1/2/3 are designed to address the advantage a larger school has over a smaller school.
If you want to keep an open tournament maybe require top 4 seeds to take a bye. At least would clean up some of the slaughters