For those who don't know, here's the basics of how the ASVAB works. It's not a 0-100 score in the traditional sense based on a percentage of right answers, it's a percentage of population based score in comparison to a baseline of students with a 10th grade education. So if you score a 50 AFQT, you fall in the middle percentile of all others with a 10th grade education. Minimum score for USMC when I was a recruiter was 31 AFQT (technically speaking CAT IIIB and higher), so in essence we would accept all but the bottom third-ish of America's young men and women intelligence (testability, anyhow) wise. Out of those, for every one <50 we would accept, we had to have two >50 (CAT IIIA and higher). Other services were more strict, USAF at that time wouldn't take anyone under 50, Army would take down to 21 on rare occasions, Navy give or take was like USMC I believe. I would take fellas with tats up their neck to the Army office because they could enlist them, they would send me the petty felons because we could take them but Army couldn't.
School wise, I knew of one we enlisted without HS diploma or GED. He had a pretty high ASVAB, 70s at least IIRC, was previously in the delayed entry but had a bad run in with his new step dad at home and bailed from the house and high school one month shy of graduation. Worked hard, kept his nose clean as well as drug free, on a whim a year later I called him up to get an update on him, was working construction and still wanted to join, but still no GED which at the time was an ultimate go/no-go, even in '05 and the thick of the wars. Long story short I called the bosses, it was the end of the FY, we were barely short of making mission for the year, and they pushed up and signed off on his waiver (Commanding General level), he went on to make a fine Marine.
Education achievement is hardly a good basis of intelligence, I had a guy with a BA from FGCU who cut an 11 on the ASVAB. I had well more than a few 90+ AFQT who had zero ability or aspirations to attend college, and typically they also wanted infantry or nothing. Whole picture person is something the services need to take into account, but in the DoD culture of go/no-go criteria for damn near everything, it's not going to happen.