Zoro and Luffy's personalities are very similar. Zoro can certainly match Luffy's power and determination. He was the first man to join Luffy that says a lot about his position in the crew. He certainly can be called the vice captain.

Talking about Zoro fighting the second class enemies. Mihawk was no way second rate enemy. He is cool character. Is he a villain or not? I dont know. Zorro fighting him will be a great moment. Is Zoro ready for him? What about Mihawk's sword. Does Zorro need more powerful swords than he already has?