The SAT and ACT are pretty easy in this regard. You can do really good at it just by practicing for a few months. Nothing like the Chinese Gaokao, which you need to study for a couple of years at least.
SAT stands for aptitude test, why would an aptitude test require multi-hundred hours of studying? All you need is to know a bit of math and how to read and you can score really well, you'd think that would be a shit test but apparently 90% of people can neither read well nor do a bit of math, so it is actually a good test.
The SAT stopped being called an Aptitude test in 1994, when they decided it didn't mean anything except "correlated to score on other SAT sessions, and to college GPA"
Realistically good test would require that multi-hundred hour build up.