User management in a multi domain environment

Currently we only have a single domain. However, due to a segmentation of our network for security reasons, we will have several domains in the future.

It should not be a problem to install collector servers in the new domains and use them to manage users and groups in the respective domains.

What I am wondering now:
Suppose a new employee starts and needs a user in all domains.
Is it possible to create all users at the same time using a single template?
I am aware that the users are not synchronised after creation, but it would simplify the creation process itself if you could select in ARM whether a user should only be created in one domain or in several domains.

If the ARM does not offer this option, the only way it would work would be to run a Powershell script after creating a user.
The problem is that you would then have to give the script the credentials for the admin account of the respective domain, while the ARM already knows these credentials.

Kind regards