I always had Ash die because to me the idea of making sure the nuke was properly made was more important than just holding the line somewhere else.

It's why in Dragon Age Inquisition, I always did the mission where I time travelled because if the enemy could go back in time to fuck with stuff, I could lose the war before it even started, even if the expense is that I lose troops who become possessed by demons. That sucks but to me the potential threat of time travel is worse than the other that was presented to me.