After all, you still need some protection against dual-stack Altgolems under Battle Defense, for example, even if it's in the late game. And as I understand it, this is more like protection against "solving the game early"?
Although, in my opinion, doing it earlier is a slightly less exotic strategy than the unknown strategy involving vampirism – it's quite rare to be able to defeat them before week 5 and still have time to use them.
I agree about the dwarves. I've always thought that this is their defense against tricksters, and starting from week 6, it becomes an unaffordable luxury.