Dyslexia and High IQ kid

I can see the value of a professional with experience with 2E students if you are looking for someone to work with the student to develop strategies. As far as testing to qualify for school services or accommodations is concerned though, can someone with more experience explain why it matters? From our one experience, D took a fairly standard battery of tests (some written and some aural). The results showed her scoring at very high levels in every category except processing speed. When the tester saw that, he administered a few more tests that drilled down in that area and teased out specific challenges that applied to her. Obviously if he had just looked at her SAT or ACT exams, he wouldn’t have been able to pull out the processing speed issue and certainly not the visual processing issue specifically, but it seem to me that in her case, any tester would have arrived at the same conclusion given a standard battery of tests. I’m new to all of this, so just trying to sort out what I need to learn. Thanks!