Although the stats for every Anito is random, there are slight nuances as some are more suited for attack while others are better at being front line meat shields. In terms of character roles in the game, this will highly depend on the equipment (armor and weapons) that you use per Anito so you can customize your party according to how you want them to synergize. For instance, you can become very aggressive and have AoE casters to open, or you can play defense with a strong tank with life steal abilities. As you ascend the towers (or descend the dungeons) you will find many different combinations that are better suited to deal with the enemies and their damage types.