For some reason there seems to be minimal overlap between the two communities and that blows my mind.
I’m not surprised at all. Microblogging is kinda hard to get. When I want to participate in some online social space, I lurk a bit on there to get the general vibe and then start or join discussion. Yesterday I tried to get into microblogging fedi (mastodon, firefish, akkoma) and I couldn’t get past lurking part because interaction on microblogging social media seems so fractured. And a lot of posts on Lemmy indicate similar problems people encounter on mastodon.