I still don't understand the question, tbh. What would be your reasoning for
a. killing all draugrs in a village to begin with, unless you want to habitate it, and
b. why would you leave one spawner intact?

Unless you want to use it as an endless factory for entrails (much as I use Greydwarf nests as a factory for resin), I don't really understand the question, as this does not get any mention.