I think having a guide or map to help navigate the different versions of each community is probably the most essential part to do this successfully.

Having distinct branding through the community name would also help. Otherwise, you'd have to create a guide where the instance would be the main branding indicator for the type of community:

Ex.

• [email protected] - general games community
• [email protected] - memes about gaming
• [email protected] - serious talk about games

Note that the actual instances can't even be relied upon to be a good indicator on what type of community is hosted there.

Now that I think of it, it might have even been one of the main causes of frustration at Reddit. It would have contributed to mod vs user tension when a user joined the wrong version of a community, like if they wanted to joke around more in a community that wanted serious discussion or vice versa.

Most of the time I see it as the user's fault. People like to think of mods as mere janitors. But they're also ultimately the one with power to steer the conversation to maintain the culture they want to foster (see the excellent /r/AskHistorians who are often vilified by the people who don't follow their standards). Otherwise you'd have have multiple communities that are essentially just the same thing.

I think a place with such a guide, plus the ability to discuss/evaluate/review mod teams and instances themselves (admins and all) would be helpful for the fediverse. Especially if admins pay attention and act on the mod team reviews because ultimately, I think communities should be about the communities themselves and not the person who happened to first register that community.

I'm not sure if I'm in complete agreement. I for one don't like how a community can be owned by just one person. But I also don't believe the community itself can be trusted to uphold a culture as the subscribers grow and change over the years. An admin can't always be in the know to make the right decision for the community and may even make it worse.

The branding/naming convention alone would at least imply that there are differences in the communities (or there would be no reason why they were there in the first place). Each had their own philosophies on what type of gaming-related content they want to talk about. You don't even have to read the sidebar of each sub to judge the type of community as the content association alone can be easily spotted even with a cursory look at /r/all.

But what happens when each gaming community in each Lemmy instance is largely similar, resulting to just the same type of content discussed ad naseum? People would just eventually converge on where the majority goes. The only reason why I would personally subscribe to similarly-named communities is if each community has a unique take that I both find to my taste.

You're fundamentally not understanding the issue here. Mastodon isn't the same kind of content as lemmy, a link aggregator and forum. Microbloging doesn't have user curation, it has algorithmic curation. The only control you have over your feed on a site like mastodon, threads, or Twitter is by who you follow and they just throw all of those posts into a endless list filled with disorganized nonsense. You don't need to centralize communities there because there is no community to centralize. It's like millions of people are in a room and they're all shouting at once. Link agregators are the exact opposite of this. There is direct democratic curation superseded by moderation to keep communities focused and topical. You follow communities that will curate relevat content to their state topic and if those communities are not centralized you can't interact with them as effectively if they were. There is no reason for any individual game or media franchise to be divided across more than just 1 page unless the amount of topics and content they can produce necessitates dividing specific facets of that community to not cannibalize the limited space the sites format allows for. Some games force esports content into it's own subreddit and this severally hampers the visibility of that game on Reddit, or they divide out the meme posts because the sub is so filled with regular postings and discussion that they would get in the way and lose nothing by being segregated, unlike esports. Franchises like star wars don't have posts about Jedi survivor or the old republic on their main sub because those games generate their own content that most people who don't play those games do not care about. So yes, there are some reasons to divide communities, but there is not a strong reason to make more than 1 community for virtually anything on a site this small. There should only be 1 place to talk about Android here, for the time being, because there are simply not enough people to sustain more than that regardless of what your feeling on decentralizing communities are.

Decentralizing any community into small groups is exactly how you kill a community. People want to feel like they're apart of a large group and that they can interact with everyone who shares that interest. It helps that community grow and by pushing them apart you're essentially forcing them to choose what tribe they want to join and inviting tribalism when in reality they're all the exact same people who we are dividing because we lack the technical capabilities to unite them.