Actually, it is fairly unusual for VCI to be average when VSI/FRI are much higher, even in mathy kids. Though of course, there are some individuals for which we would describe this profile as one with significant relative strengths, rather than significant relative weaknesses. But those persons usually perform closer to their FSIQ in terms of their reading/writing achievement. (The same applies to the relatively low WMI.)
What were the VSI & FRI? I'm assuming in the 130s. If so, that is a ~2 SD difference between VCI/WMI and VSI/FRI/PSI, which is pretty substantial, and consistent with a similar magnitude of difference between his language and mathematics achievement. Assuming there are no interfering factors (e.g., that he is a fluent speaker of English), this would be suggestive of some concern.
Do you find WM or language challenges IRL? Does he have trouble remembering or following through with directions? Ask frequently for repetitions? Often say, "huh?" or similar? Struggle with expressing himself clearly?
