Originally posted by Marshmallow_Fox:

I don't think you're aware of the world of hurt this task would be for anyone trying to implement sensible AI partners into a survival game of this nature.

This isn't like an Age of Empires game where it's simple pathing and tasks on a 2D plane, and even in those games, the AI very often gets stuck, picks the worst or impossible path to reach a destination, or needs to continually be manually controlled because they forget what they're doing or can't figure out how to get there.