So..
Your school's teachers have been grading Year 10s, since September, in all subjects, on what their current work might get if they presented exactly the same work in a GCSE exam that happens at the end of Y11, but for which even sample papers have not yet been created?
How do they know whether this work might even appear in a GCSE paper - ie that the question type that they have asked, or the task that they have completed is markable in that way? Let alone the marking criteria all the way down to 1?
I'm sorry, I had assumed that you were only talking about Y11s being marked on mock or internal exams in English and Maths for the upcoming GCSEs, which they should get between 7s and 9s in.
i genuinely hadn't realised that you were talking about Y10. I shall cease to engage at this point, because that is straightforwardly bonkers.