All else aside, there is a system level issue if DfE goes ahead with its plan for the reporting of deciles.
As is quite clear from past events, awarding bodies in England do not have a great track record in writing exams that are consistent from one year to the next. This issue has been mitigated over the years by reference back to KS2 outcomes, which in turn were linked to assessment levels. So there was a backstop of criteria to enable a standardisation of KS4 outcomes. This argument does not require you to believe that assessment levels are the best thing since sliced bread or that CO is necessarily a good methodology. The law of large numbers enables us to assume that across a cohort the ups and downs even themselves out.
How will this work when the reporting mechanism at KS2 is a decile? Unless there is still going to be some form of levelling running in the background it will be very difficult to ensure that year to year KS2 assessments are standardised. Without this, it will be tricky to operate comparable outcomes or any form of similar system. I find it hard to see how KS4 outcomes can be standardised from year to year.
If there is going to be some form of levelling running in the background, what will it be? Will it be secret or published? If published, then we are back to levels.
Without an answer to this there is a risk that within a few years we won’t have a clue if standards are going up, down or sideways.