I don't know anything about the WJ test, but with the WISC, I know you can get a GAI when there's a large enough discrepancy between the indices. My ds's processing speed was low average and that fact definitely lowered his FS. In fact, in more balanced profiles, the IQ ends up higher because it's rare. I imagine if your ds took the WISV IV, then you could get the GAI, which would be a better measure of his abilities and even perhaps mre precisely see how his 2e affects the overall score. Maybe the WJ test does that, too. As I said, I don't know anything about that test.