If your school uses the Lenovo N22 Chromebook, then you should have the best Lenovo Chromebook protector out there: The Cranium Hard Screen Protector and Whiteboard. It's designed for the Lenovo's unique screen. I am not totally sure what n22 does that requires such a screen, but I can assure you it will be worth your investment to protect the Lenovo Chromebooks.
I never realized that schools choose different computer models than businesses or individuals. I could see some schools looking for more rugged designs. Beyond that, it's probably just salesmen adding to commissions, especially when the feature involve amped up capabilities students will never use in order to move new products and decommission older ones. I once found five computers in a storage room because they'd been decommissioned in the district. I hooked them up, and students used them in my room. In less than a month, I was told to stop using them, and students grumbled. Even though the machines were about five years old and sat in a storage room for a year, they were not to be used. Don't go that direction with your Chromebooks. They are cheap, fast, and strong, meaning you can use them daily. The Cranium makes them stronger, like putting bullet-proof glass and run-flat tires on your daily driver.
If you have a whole school district in need of Chromebook protection, send Educbana a message.