We are required to submit to the judges that God has established.
The authorities that exist are established by God (Rom 13:1b).
If judges are appointed, then the person who has the power to appoint them has the power to distort justice. Judges are appointed by kings or politicians lose their independence, because those who appoint them can also remove them. The people lose their freedom, because they must take their cases to the judges who are appointed. They are not free to choose the best judges.
The Bible describes a better system. Judges emerge as people start taking cases to people who demonstrate wisdom. If a person gets a reputation for making wise decisions, more and more people will submit their cases to them.
Paul said that we should submit to excellent judges, because that is how excellent judges emerge. They are not appointed. Ordinary wise people become judges, as more and more people choose to submit to them.
A judge cannot impose their authority. Free people give authority to the best judges by submitting cases to them. Excellent judges emerge as people submit their cases to the better judges. Poorer judges will get less and less cases, as people hear about heir mistakes. When a judge goes sour, people will stop submitting to him altogether and take their cases to better judges. Paul is saying that the judges that have emerged in a free society are the ones that are established by God. By submitting to excellent judges we allow God to bring into being the judges that he has chose.
Moses, like many leaders, believed that he could do the job better job of judging than anyone else, but exhaustion proved him wrong. When he set up a system of judges, he thought he needed to appoint them, but he was acting on the advice of Jethro his father-in-law, and not on a word from God.
All Moses really had to do was tell the people to take their cases to the people in their tribes and communities that they already trusted (Exodus 18). He actually found that God already had judges in place. The people knew who they were, but Moses had not acknowledged them. The new system worked, because God has put the judges in place. The proved to be effective judges when they were allowed to do the task.
They served as judges for the people at all times. The difficult cases they brought to Moses, but the simple ones they decided themselves (Ex 18:26).
There is no legitimate judicial authority except from God, so the people that come to be “the judges that are” are God’s order for justice. The judges that exist, (because people trust them) are those placed (tassa) by God.
Only those judges that come in to existence through voluntary submission have a legitimate authority. Their task is to apply the law of God. All other political powers are usurpers of God’s authority.