Not really. The issue is that some people want to have exactly the same setup and library (including all the edits that they have made) in more than one location, and that is difficult to achieve manually - and Roon has no way of doing this automatically; at least currently.
However, it is certainly possible to move local content between Cores using USB drives holding the content.
There’s no requirement to have the same endpoints on each Core - they are independent Cores, after all.
And if your Library is using content from streaming services (Tidal or Qobuz), then this content will be automatically synchronised between multiple Cores - no manual intervention required.
It’s when people try to backup the Roon database from one Core and restore it to another that issues are likely to arise. Here be dragons - personally, I don’t advise it. I just treat separate Cores as separate - and know that I can share local content by moving drives.