or, I suppose *more* defensible, the decision to take refuge in a crypt (since I just assumed there'd be a spell radius or the dead would be too well-secured to attack)
hiding the women, the weak, and infirm in a crypt while under assault by a Lich King that can raise the dead at will to do his bidding? What could possibly go wrong with that plan? That's a mistake Tyrion would only make in the final season due to IDGAF writing.
---
The SBA has closed for business, we thank you for your patronage Assassins. ~there's always free cheese in a mousetrap.