Is that closer to the actual cognitive mechanics, or closer to a myth that's nevertheless useful for classifying people?

For example, in some empirical behavior research, person A seemed to have better snap decisions but poor at follow-though, and person B seemed to be asking about details... Has that nailed some key innate difference in how A and B actually think, or merely -- for purposes of, say, assigning military conscripts to jobs, or a huge corporate hiring machine that can't care beyond commodities -- at least it's a classification?

Maybe it's better than chance at predicting exhibited behavior (absent training), and we don't know that it reflects the actual cognitive mechanics?