You haven't understood the difference between a tutor group and a subject set.
I may have misunderstood, as in some schools, a tutor group might refer to the class students are in for a specific subject, similar to a set. If by ‘tutor group’ you mean the traditional ‘class,’ my point still stands. There isn’t a strong rationale for assigning a class based on an entry test for all other subjects without sets. The example you have doesn’t seem like a good practice to me.
How on earth are primary schools going to conduct multiple banding tests for masses of different secondary schools?
DD sat 4 different banding tests in Y6 - some were just NVR, some were NVR, VR, English and Maths. Every school had it's own system and they were not all in the same borough.
That is the whole reason to consolidate this and apply the intake randomess more universally when the 11-plus exam is scrapped.
The comprehensive banding test, as it is called, aims to do fair banding for mixed ability, which does not require preparation or a bespoke format. Every school is not in competition for creaming off the best students. There is no need for a small variety of different formats, and indeed, for multiple boroughs, it can be shared by one set of results if required.
PS. You don't need to tell me why schools use banding tests, or how they work. Believe me I would probably be on track for top grades in a GCSE on school application processes.
I believe you probably familiar with this specific logic. And you should see there is little point to have multiple different round of banding test. However, it seems that some other parents in the thread, who apparently only know how the grammar application process works, don’t have a good understanding. Some might even claim that it is not much different from the grammar test in intention.