When building out the database of recommended Lemmy communities, I think it makes the most sense to prioritize the communities that belong to instances focused on a specific topic over communities that are based in a “general” instance, even if currently the community is smaller in the topic-specific instance.

For example, for an user coming from reddit and signing up via a “fediversed” instance (like alien.top) it would make more sense if they see that the anime subreddits are on ani.social, the rpg/board games are on ttrpg.network, the programming communities are on programming.dev, the basketball ones are on nba.space, the NSFW communities are on lemmynsfw, etc, etc…

This will also avoid the issue that I am currently seeing where some communities have multiple entries in the recommended database due to the initial migration where each user was just trying to replicate their favorite subreddits in their own server they signed up for.