Your admin users data are on the tables admin_user and admin_passwords in your Magento 2 database, you can use these commands to export and then import in your second store:
$ mysqldump -p --user=username dbname admin_user admin_passwords > myAdminUsers.sql
$ mysql -u username -p -D dbname < myAdminUsers.sql
If you use a database prefix, don't forget to use on these commands above.
Single Responsibility Principle (or SRP) is one of the most important concepts in software development. The main idea of this concept is: all pieces of software must have only a single responsibility.