Why are startups often disasters internally, as PG says in one of the linked articles?
The quote in question: "Practically all start-ups internally are disasters"
Not just "often", but "practically all" start-ups. It's true in my experience, and not necessarily a bad thing. Of course, it would be great if everyone acted thoughtfully, didn't let ego get in the way, planned things just enough (but not too much), etc., but that's not just not the way it happens.
Acknowledging this fact, getting okay with it and still forging a highly functional team in the midst of such chaos and tragedy is the key. That's a tall order.