> The IQ tests that I was administered as a kid I remember as being primarily focused on abstract pattern recognition, which is what I think of when I think "IQ test".

That's just one specific IQ test, Raven's Progressive Matrices.

> I guess I always assumed that the ASVAB was used a bit more literally. "Ah, this person is barely literate, but knows all the parts of an engine. TO THE MOTOR POOL"

From https://www.officialasvab.com/applicants/faqs/ :

> there is only one exam, the Armed Services Vocational Aptitude Battery, or ASVAB for short. The ASVAB has 10 tests. Your scores from four of the tests—Word Knowledge (WK), Paragraph Comprehension (PC), Arithmetic Reasoning (AR), and Mathematics Knowledge (MK)—are combined to compute your score on what is referred to as the Armed Forces Qualification Test (AFQT). Scores on the AFQT are used to determine your eligibility for enlistment in the Army, Navy, Air Force, or Marine Corps. Scores on all of the ASVAB tests are used to determine the best job for you in the military.

You have to clear an IQ threshold to be eligible to enlist at all. Only after you're smart enough to be in the army will they consider which jobs you might do relatively better in.

> That's just one specific IQ test, Raven's Progressive Matrices.

Not OP but thank you, now I finally know what that test that I took as a kid is called!