Reddit had the same issue. Often there were multiple subreddits created for the same topic. Usually, eventually, one would win out. I expect the same thing will happen here.
Another solution on Reddit, of course, was to create a multireddit that included all of these subreddits. I'm not sure if that's possible on Lemmy at this point, but if not I hope it's something that gets implemented. It immediately solves that issue.
In the meantime, just subscribe to all of the similar communities.
That's interesting, because I always used the old.reddit interface and hated the new one. Lemmy reminds me of old.reddit so I'm very happy with it.