Updated standings through this week (with the exception of PP, will get around to that).
Last week sucked.
I can't think of a time a coach has been fired like that, although the NFL is admittedly 100 years old now so there's plenty of room for something crazy to happen. That said...it's really rare (maybe even unheard of) for coaches to be hired from outside a team mid season. They're almost always promoted from within, generally because trying to get a grasp on a playbook in the middle of the year is really challenging.
I don't think any outside coach could understand the playbook any worse than the current Cowboys coaches.