Exactly. I added the entries from the spreadsheet onto my own excel. The number of submits in May are as much as the ones submitted in June, July, August and September combined. I've seen another spreadsheet in a Telegram group from one Asian country (about 200 data-points) and they had a very similar pattern mentioned above.
They'll be done with May submits by the end of this month or the middle of December. This means they spent (half) of September, October, November and half of December for May submissions. Take it as about 3 months of full workforce. This means, if all goes well, by April they could be done processing the DS's submitted before the start of fiscal-year. I submitted in mid-September (estimate to be current during last quarter), and this is why I see hope.
And for the docs processing, once the backlog piles up (about time I guess), they'll go by the case number. They're probably doing the docs processing by CN now, but could be come more visible in the coming weeks.