You need to make their personalities different or else if you're not present there then you can say goodbye to all the hard work you're going to do to make up for their weaknesses...
@cullinaire I bet you by the time I catch up to the most recent chapter, the comment sections will still be the same people saying the same things about all of this. It might as well be like a law of physics or something. Perhaps even more reliable, actually, since we can't honestly say we understand any of those completely.