Eh, I meant Dead Beat, not Death Masks. As a GM, I can always get more zombies to get the job done. 10 is not enough? The guy has 20. 20 is not enough? The guy has 50. If I want to, I will huff and I'll puff, and I'll break down your puny ward, regardless of what you do. Fate solves this nicely with compels.
In the case of DB, it feels like a compel as well.
"Sure, you thought you'd be safe inside your wards, but have you planned on them holding against a horde of zombies that just fling themselves into it and discharge it a little bit every time?" *holds up a Fate point*
-"Huh, I guess I haven't. We better see that we get out of here, the wards won't hold against that for too long." *takes Fate point*