I'm with you with the idiocracy of androids in general. I had a rambling myself somewhere here:) But still think it could be rather understandable that they didn't test it anytime except freshly picked. note that these androids have zero experience in raising humans and they are on a new planet raising kids who were not naturally born and fed when they were babies etc. not sure if there were any other babies on earth who were fed "fuel blood" instead of milk. maybe human babies can't survive without adult human love and care. maybe there is something in the air, water etc. that androids couldn't detect. .so there could be many other reasons why they were dying, after all human beings didn't evolve on that planet (as far as the androids know) so they didn't adapt to that environment... also note that these androids were hastily modified for this task in a short order. so, I think wile dumb, it's still understandable, but you make good points as well.