Mosiah does set up the judges so that they are not the ultimate authority in and of themselves. Using the principle of the voice of the people (where the majority will want the right) he creates judges who also are “the people.” By creating the higher judges and the court of “peers” Mosiah creates a situation in which the judges themselves have a means of becoming the “voice of the people” to make sure that the right thing is done.
Once again, notice the use of the term “voice of the people” in verse 29. From our modern perspective, it would appear that this court of lower judges would somehow poll the “people” or take votes. Were they to do that, then the court of judges would not be needed at all. The judges judge by “the voice of the people” because they have sufficient numbers to assure that the right thing will be done. This is not an appeal to a vote which would remove all function from this court.