Once dead, Rhadamanthus will judge the dead souls from Asia, Aeacus those from Europe, while Minos will have the privilege of a final judgment if the other two are at a loss about anything.
Is Socrates suggesting that Zeus' sons, Rhadamanthus, Aeacus, and Minos, are to be the afterlife substitutes of earthly witnesses?
While beholding with his soul the soul of the Great King, Rhadamanthus does not know that it belongs to the Great King: "whenever the judge Rhadamanthus has to deal with such a one, he knows nothing else of him at all, neither who he is nor of what descent, but only that he is a wicked person.
True, Rhadamanthus does not know that the Great King is the Great King when he sees his soul.
We can notice first that Socrates does not say that Rhadamanthus will see the Great King's past actions.
While the Christian God is omniscient, Rhadamanthus and his brothers are not.