The SAS has the same kind of relationship to age percentile that the IQ score has, except that the CogAT uses SD = 16, if I recall correctly. It is carefully not called an IQ.

The nonverbal section of the CogAT is probably better compared to the Fluid Reasoning Index of the WISC-V. The small variation in scores may or may not be due to that difference, as the instruments are not really all that similar at that level.

...pronounced like the long vowel and first letter of the alphabet...