Problem definition:
Currently, there is no option to merge two or more user groups.

Suggested Solution:
Add an option to merge two or more user groups into one.

Why is this important:
When managing large amounts of users and groups this feature will provide flexibility to merge two groups and replace the tedious process of moving many users from one to another group.

Workaround:
Manually add users from one group to the other before deleting it.