True, about the scientific side of this, but I rather doubt, to an ancient like Job, this is what it meant to him. Nor to God either, who, in scripture, defers to the times people live.
To the ancients, the “girding” of the loins meant, in our modern lingo, “lock and load.” Orion the warrior with his loins girded for battle. His cords, or belt, conveyed that thought to the ancients. God who formed the constellations, has Orion pictured thusly, the question is put to Job, can he change this? can he loose those cords?
Likewise, the Pleiades.
I completely agree. Such scientific concepts were not yet even dimly conceived. But I expect that you're well aware that many, many times God inserted multiple meanings into Scripture, and this is simply another.