5 and 10 are the same question. And to answer that question specifically, you *can* run it that way, but it's better if you don't, at least in other PBTA games. in the other PBTA games I've read, it's made clear that playbooks aren't just your class, they're also your role in the narrative, and guidelines for your character's story, so it can be done but it can feel like stepping on eachother's toes if two people are taking the same one.