Every spirit in the Goetia carries a rank, and the ranks are not infernal. They are the ranks of a European court and a European church, borrowed wholesale.
The list runs king, prince, duke, marquis, earl or count, president, prelate and knight. Marbas is a president. Set against a real early modern polity the fit is close but not exact: the secular titles are feudal and the presidency is administrative, the office of a man who chairs a council or a court rather than one who holds land. Prelate is ecclesiastical, and its presence in a demonic hierarchy is a small joke that would not have been lost on a seventeenth-century reader.
Each spirit also commands a number of legions, which is a Roman military unit, so the structure imagines a court, a bureaucracy, a church and an army at once. Nothing in the text ranks the ranks against one another. It is never said that a king may command a duke, or that a president outranks a knight, and the ordering of the catalogue does not follow rank at all, kings appear at positions one, nine, thirteen, twenty, thirty-two, forty-five, fifty-one, sixty-one and sixty-eight, scattered through the sequence.
The hierarchy is therefore decorative rather than operative. It tells a reader what sort of thing each spirit is imagined to be, in the only political vocabulary its compilers had, and it does no structural work in the text.
This is characteristic of the corpus generally. The Goetia does not describe an alien order. It describes a mirror of the world its compilers lived in, populated by figures who hold offices that world would have recognised, and the mirror is a good deal more informative about early modern Europe than it is about anything else.