In that case, I'd use the static site generators I mentioned earlier and write your content in Markdown. You can probably do multiple sites in one project, but, if not, you can definitely just have different folders for each and run a script to publish them all at once. Performance wouldn't be a problem either way. I know Hugo can process thousands of pages in under a second.
AI isn't the magic wand they make it out to be, especially on commodity hardware. I've seen some make passable English nonsense, but it wouldn't be engaging content generating any kind of click through. You really need a person who understands the audience. Software and AI can help, but they won't do the job on their own.