In a corporate environment, you no longer need to assign an individual apple id per device. You use an mdm instead.
Consider Apple Business Manager. Select an MDM, Mobile Device Management.
Business overview"
https://images.apple.com/business/resources/docs/iOS_Deployment_Overview_Busines s.pdf
Education overview:
http://www.apple.com/education/it/dep/
Apple Business Manager
Manager is a simple, web-based portal for IT administrators to deploy iOS, macOS, and tvOS devices all from one place. You can configure device settings, create accounts
for all your managers , and buy and distribute apps and books.
https://help.apple.com/businessmanager/#/asm6a88f692e
lots of details: https://beta.business.apple.com/static/docs/beta.pdf
Upgrade your organization to Apple Business Manager
https://support.apple.com/en-au/HT208817
MDM -- Mobile Device Management allows an administration to manage your iPad and iPhone devices.
Airwatch, Apple Configurator with Apple Profile Manager, GroundControl, Meraki -- is free or was free, MobileIron or Zenprise
For a comparison see this page:
http://www.enterpriseios.com/wiki/Comparison_MDM_Providers
Apple Business Manager incorporates:
DEP, Device Enrollment Program, sets your business as the owner of the device and locks down the device with an MDM. Apple's Device Enrollment Guide.
https://www.apple.com/business/docs/DEP_Guide.pdf
VPP, Volume Purchase Program, gives you a discount when you purchase apps in quantity.
http://www.apple.com/business/vpp/
http://www.apple.com/education/it/vpp/