On the topic of multiple people playing the same archetype: It's fine. It merely means you need to adjust and show what makes your character unique. Develop them. Heck for two people with the same archetype you can set up such classic relationships as apprentice-mentor or comrade-comrade, battle brothers, rivalry... In fact it irks me when a person can't take seeing more than one of the same archetype. I look at it like a special snowflake syndrome. There are people who share similar skills and hobbies to you in real life, is it that outrageous the same might occur to your character?

What makes a character unique isn't their background or their role. It's how they deal with a situation. Their actions determine who they are, not their past or abilities.