I think the focus of all the assessment is to identify children who are challenged. With the explosive increase in learning delays and diagnoses of Autism in the recent decade have also come studies which show very definitively that the earlier a learning disability is identified and addressed, the better the outcome is for the child. As early as 6 months old, a professional may be able to uncover difficulties and begin to work on them. And the earlier this happens, the better the child will do.
You hit on the right note. The needs of a child will develop but again, every child is born and raised different, and when compared to other kids of their own age, a child will feel isolated if he/she is not up to the 'recommended' national level.
Also, it is thought-out and the ratio of a teacher dealing with each child is appropriate, but I wonder if it would be enough from the long-term perspective.
"We retain our strong view that the staff to child ratio of 1:13 ... is too low and should be 1:8. This point has particular pertinence given the framework stipulates that assessments through the foundation stage take the form of observation via 'look, listen and note'."
Most importantly, what if a child is categorized as special just because he/she doesn't fit the National scale but is learning at the right pace? That is more discouraging than having to scale the curriculum better to fit the child's needs.