Greenlotus if I understand right you expected your DD10 to do better than your DD12 on the test. Is that correct? I am not sure this would be the case. Unlike WISC the EXPLORE is not an IQ test but a knowledge test. So age and maturity probably have a major role to play.
I would have the same overall assessment on the DYS numbers for EXPLORE. The numbers have probably been created based on the same percentile expectations as of those on WISC. But because of the age issue I suspect hitting the percentile on EXPLORE in younger grades is rarer than on the WISC. Hence the issues of DYSs not hitting the numbers in EXPLORE.