I can’t image how you adequately control 3000 teenagers.
At my HS, 3200 students, no metal detectors, no fenced in campus, no school resource police officer, just a vice principal with a paddle board he used on unruly students, when needed. Most boys carried a pocket knife. On practice and competition days, members of the rifle team carried their firearms to class, because the lockers were too small to fit the gun cases. We had no shootings, stabbings, or any mass casualty events.