You may want to set up a pilot within Teacher Dashboard in order to gradually roll it out within your school.
Create a Whitelist of users to ensure that these are the only users who show within Teacher Dashboard when setting up classes, or sharing assignments or files with individuals.
Log into Teacher Dashboard as a Global Administrator and click on Global Administration from the top menu. Go to the Global Settings page and click on AAD User Sync.
From here you have the option to set up a Whitelist of users or a Blacklist of users.
To set up a Whitelist, ensure the second radio button has been selected: "Only sync users listed below" and start to enter the users email addresses in the text field using either a comma separated list, or enter each email address on a new row < br/>
When you click on Save, Teacher Dashboard will only show the users who exist in the whitelist, and will remove any who were previously shown but are no longer in the whitelist.
At any point, if you need to amend the whitelist, you can add or remove users and click 'Save'