‘Then Nebuchadnezzar the king sent to gather together the satraps, the deputies, the governors, the judges, the treasurers, the counsellors, the sheriffs, and all the rulers of the provinces, to come to the dedication of the image which Nebuchadnezzar the king had set up.'
Having made his grand gesture Nebuchadnezzar wanted it to be admired. And he was determined on a show of loyalty. Such dedication rites were customary in antiquity, and this is in keeping with what we know of ancient Babylonian rites.
‘Satraps' is an Old Persian word signifying ‘kingdom-guardian', ‘deputies' and ‘governors' were Semitic, but such loan words were common (and when he wrote Daniel was in a Persian environment). The order of the titles probably indicates their grades.