Managing client accounts with re marketing campaigns

Hello, I'm looking for guidance on how to manage a client accounts and appreciate any advice!

I'm planning on driving traffic to a new domain where my landing pages will be hosted separate from the clients primary domain.

The question I have is does it make sense to run a re marketing campaign from the new domain account or do I need to run the re marketing campaign from the google ads account associated with the primary websites domain?

I appreciate any help or advice!