Hi, with our current setup we're using "Microsoft for schools" for our student e-mails, this was done really to test the water so linking them to our AD at the time didn't seem needed, when Microsoft then linked these to Office 365 it was then decided to push the use of it so linking our student AD accounts to office 365 became needed. Our students use a different email suffix to the staff.
Example
students = @schoolstudent.net
Staff = @school.net
domain = .school.pri