Nuclear weapons are mostly a threat to cities, and a zerg rush build would just not build any.
I think that if all we get is skill cloning for formally verifiable tasks, that is not "AGI" and does not doom us. It probably won't even doom software engineers, because their whole job is also not formally verifiable. I don't trust that the next ten trillion dollars of AI research won't give us data efficient continual learning and agency on par with humans, which is what I would call AGI.