If you want to continue down the linked page route that will work but you have to copy each linked page as individual pages, it does not copy/create child linked pages automatically. You could create a "base agent" node in the content tree then copy it when you add a new agent. You still have to update the other agents with any new or removed content though moving forward after that new agent is copied.
Otherwise I'd recommend setting up a "global" folder for those learning center items since they are all the same content. Leave the URL structure at the root of the site under /Learning-Center and just dynamically pull them all into each of the agent's areas. If you specifically need the URL to be specific to an agent then create a route for the pages.