Y’know, I was just going to mention Fandom. I have no idea how well this will work for Wikipedia, but I know something like this can work great for games.
Fandom is straight up harmful to game communities, and I think federation makes a lot of sense with per-game / series / etc. instances.
I’ll look at this a bit more later, quite interesting idea.
I think this is a known problem. I’ve seen it recommended a lot to moderate communities from the same instance.