They know they can mask their stupidity by saying the right words, mimicking praised patterns, echoing embraced platitudes, rearranging congealed forms, and imitating accepted arguments.
The correct combination of performance and content will make them appear intelligent in the eyes of other smart-stupid people. At the end of the day, that is all smart-stupid people really care about.
Naturally, they remain oblivious to the sinister smart people who make "smart-stupidity" viable by encouraging and promoting its widespread distribution and celebration. Smart-stupid people never question how or why they got to where they are, even though "where they are" is clearly and palpably far above and beyond where they should be.
They are thoroughly convinced that their intelligence is authentic (they have the accolades and baubles to prove it, after all); thus, they remain incapable of registering, let alone comprehending the "fake it till you make it" mantra.
To paraphrase a quote by Stephen Vizinczey, contrary to the reigning ideologies of the day, smart-stupid people are living proof of the inconvenient truth that education tends to fortify stupidity rather than cure it.
On the other hand, stupid-smart people are generally "naturally" intelligent individuals who possess the potential to think for themselves but choose to forgo that option, usually for expediency. Like their smart-stupid counterparts, the stupid-smart are not immune to the temptations of the System and all the enticing perks it offers.
Unlike the smart-stupid, the stupid-smart recognize System ideology as bullshit but rationalize their submission to it via "gotta make a living" or "can’t beat them, must join them." The stupid-smart largely comprises intelligent people who willingly and unrepentantly participate in gross dishonesty for the sake of pay, privilege, and prestige.
Below this is another, less visible level of stupid-smart people — the captives of ego and intellect. This category of stupid-smart is the most tragic because they honestly believe that the solutions to life, the universe, and everything reside entirely and exclusively within the intellect.
To put it bluntly, this category of stupid-smart people is so genuinely smart that they cannot get out of their own way.
They seek truth through logic, mathematics, laws, and formulas, convinced that the essence of Creation and spirit can be determined and comprehended solely through such means. They remain entirely ignorant of the fact that the best such truth-seeking logic can provide is knowledge of reality when what should instead be sought is truth as reality itself.
The above helps explain why stupid-smart people, despite their high cognitive abilities, rarely qualify as geniuses.