I'm leaning more towards MBTI or another personality test because it doesn't just establish a hierarchy, it establishes an entire caste system. MBTI provides sixteen different personality types, so each of these could be a different caste in society, with people tested as being in one personality railroaded for life on a particular career path. A personality judged to be more personable would be assigned to caretaking professions, while those that are less personable but more analytical would be engineers, and so on. I also think this moves the idea away from the mandarin system.
Instead of being just a shitty totalitarian regime, I imagined it being functional but deeply flawed. The personality test is more or less accurate for most people, and generally it gives people jobs and career paths that they are happy with. The down sides come with the test not being 100% accurate and people getting stuck in roles they don't like, or people changing as they grow and having a similar problem. And of course, a select group of personality types are geared towards leadership, and of course said leadership is intentionally teaching their kids to take the test in such a way that they'll get picked for leadership too.
This would, of course, go in the technocracy chapter.
EDIT: I like this idea enough that I'm going with it.