How do Biblical Unitarians who accept Jesus’ sinlessness understand this argument?

1. All men are sinful. 2. If Jesus is not God, he is a man. 3. Thus, if Jesus is a man, he is sinful. 4. Jesus was not sinful. 5. Thus Jesus must be more than a man. Premise 1 is merely an acceptance of Romans 3:23. Premise 2 is what I think the BU position is, but feel free to correct me. Notice that for premise 5 I don’t explicitly state that Jesus is God, but I do state that he must be something more than just a man. So my question for the Biblical Unitarian is this: is my argument flawed, or is Jesus more than a man? If so, what?