No built-in way. Not anymore than multiple subreddits for the same purpose. Eventually one will become the more popular. It’s nothing new.

Treat them like different subs like /r/askreddit and /r/trueaskreddit

I see this as a feature and not a bug. A reddit sub can be taken over by a small but vocal group of users or mods rendering the sub distasteful to the general public. Very little can be done once that happens but here you can “vote” with your subscription.

One will become more popular over time. Even still, one might attract one kind of community and the other a different kind of community. That’s sort of why there are different instances right? It’s due to a fundamental difference between Lemmy and Reddit.

I don’t believe there’s a way to bring them together beyond subscribing to both and using your subscription view. There are Github issues open about this idea, so it’s being considered but hard to say if and when they’ll be added.

That thread does raise some good points about automatically grouping by name. Some instances may use a name maliciously or ironically, their posts would end up in the same group.

And we don’t necessarily want to prevent fragmentation, it can be a good thing to have multiple sources. If lemmy world because problematic and gets defederated, you won’t lose asklemmy as you’ll still have the Lemmy ml asklemmy community.

Hopefully one will die, so that the other will flourish or maybe both will flourish?

Cool be rather cool if communities could merge together a cross instances.

There currently is no way - and in my opinion should be no way to prevent duplicate communities across instances. One community will eventually become popular enough to be considered the de facto community, though we shouldn’t force interaction with an instance simply because they have dibs on a community name.

Less discerning users can subscribe to both communities.

Yeah, I think this is going to be an issue/ something that the community is going to have to think about. It actually makes more sense for lemmy instances (like wallstreets.bet) to focus on particular subcultures/ types of communities, rather than being catch alls. This has a couple advantages in that you can replicate some of the structure of reddit (like having tagged posts), and it allows federation to focus on connecting to things that makes sense. This way resolves the duplicity issues.