We have no idea how many real deaths have been attributed to Covid to hide the real cause (I didn't realise this could happen until my mother died just over a year ago...not from covid but there was something deliberately left of the death certificate by request). So if someone died on a Covid ward/nursing home, possibly that is what goes on the death cert.
We also have no idea (and seemingly the government too) as to the number as every so often we suddenly get catch-up numbers, like a few days ago we got some from November...and we all remember the spreadsheet fiasco of track and trace....
So basically, we are guessing numbers to try and predicted what is essentially a made up number anyway. For all we know, there is a wonk in London who gets woken up at 5pm to pick a number and go back to sleep. Or maybe picking the number is now what Paul the Octopus (remember that) is doing...