Now I don't get at all how the automotons couldn't move for the longest time despite knowing that it was a fake Francine. But let's set that aside. Why in hell tell them it's a fake? If she had just kept her big mouth shut and said nothing, even if the the automotons could guess that its a fake, without being about to know for sure, it would have taken alot longer for them to break free.
But I guess shirogane got to brag and jeopardize their one and only goal and reason for living now and then.
Also, why not order them to destroy each other with the fake? Why only order them to kneel?