Exactly - it's occasionally done by hand. I think the mods do a fantastic job, but this is one place where HN could be seriously improved. There are, on occasion, just so many duplicates, there is a real need (in my mind) for a proper method to clump/cluster them.

The submissions about Finland's 800 Euro basic income is another example - there are 12 or more submissions of that story, with more than one discussion.

There are more.