I have a sharded cluster, and i inserted 1 billion documents into an unsharded collection.

I then sharded that collection, and the balancer distributed all the chunks to the other shards. Running a count() on the collection yields a wrong result; the first shard shows ~1 billion documents, and the other two show 333 million each, in total ~1.666 billion documents. I can see the count going down with 200-300 documents each second. This means it would take >20 days to complete the delete, but it would only take 2-3 days to drop the collection and reinsert the data. Is there any way to make this process faster?

I'm using mongo 4.2.1