WPML thoughts and processes

I have a client that is going to use WPML. They have a US site and then they have separate sites for Mexico, EU, Canada, etc.

Any time I’ve use WPML it’s been on versions of the site that are exact duplications on separate domains. And they’ve been on sites where they were already established, not freshly installed.

These sites I’m looking at are all unique. They have different versions of wireframes and different content — some have a lot more content than others, etc.

What do I need to know to wrap my head around this project?