How many times have you been part of a group or team where there is at least one person who has to be a stickler for keeping things on track? They correct you if they feel you’re wrong, and/or make sure everything is done right. I think it’s a rule of life that every group has to have someone like this in their life in order to keep everyone on track whether it’s their job or not (I’m laughing here, because I know people like this). These people can (but not always) cause tension in your story. So if you want to spice things up a bit, included one of these types of characters within your story.