Lemmy doesn’t really have much in the way of an “algorithm” and it really shows with stuff like this. Mbin can combine posts like that and show comments from all of them, but I think it shows all posts in the main post view, it only combines the comments. I really hope in the future Lemmy combines crossposts into one posts. It’s something an app could do. But I’d love to see it in the default UI so it hopefully encourages all apps to support it too.