Dbat - the SBV and WISC WMI measures are different, but most people would say that the SBV measures are gentler/kinder than the WISC (for most children). Possibly your DD did not fully grasp the SBV WMI requirements, did not like the tester, had a bad day, or has significantly improved over time OR is better suited to the WISC method of testing. My 2E DDs WMI was 13th percentile on the WISC at 7.5yrs, 2 years and a lot of remediation later it was above the 85th on the SBV and around 80th on the WISC. So for her the SBV was "easier" but also she changed over time.
Back to the actual topic - my question is does the prodigious child start life with such yawning gaps in ability or does their interest/talent in one area stunt their growth in other areas through neglect. My children aren't remotely prodigious but I often wonder how much their weakness(es)are nature and how much is failure to nurture... My eldest I think has developmental coordination issues. She was NEVER going to be good with balls and we gave up trying. We forgot to try at all with #2 (and #3), the second two might not have been so naturally hopeless with balls.
