What is the quickest way to provide the data access for multiple inventory organizations?

Summary:

We need to have a bulk data provisioning option to provide the data access for multiple inventory organizations.

Content (please ensure you mask any confidential information):

There are 400+ Inventory Organizations and around 20 users need access to all 400+ Inventory Orgs.

Also, in future, if any new user is added into the system, then he/she might need the access to all 400+ Inventory Orgs.

Adding the inventory data access one by one is very much time consuming and tedious process. Business is looking for the efficient approach in this case.

Version (include the version you are using, if applicable):

24C

Code Snippet (add any code snippets that support your topic, if applicable):