Using Multi-DB for WPMU site, but local DB for cPanel sites and standard shared hosting.

I'm working on a niche market Buddypress, WPMU, and shared hosting cPanel site.

Since it's a bit of a hobby first, business second, I'm setting up the servers off the bat on a 32GB E5 dedicated server.

My initial goal was a cPanel/web server, a remote database server, and a dedicated DNS server. Those are all setup, but I've been having an issue with grant permissions through cPanel on this remote DB server.

So I've adjusted my concept to be the web cPanel server will use local MySQL. And I'd like to setup the remote DB server with Multi-DB just for the WPMU sites. I'm hoping this can resolve the cPanel issue since I won't need to generate databases/users separate on the fly.

So I guess my main question is -can I use Multi-DB for the WPMU site since I can pre-create the users and permissions on that server instead of being created from a remote server.

Is that how it works? Pre-create the databases and assign the db user from the plugin?