Okay so i was just thinking the other day about the conversation Ozpin, Ironwood, Qrow and Glynda (donno if i spelled that right) were having with Pyrrha in the Vault when we first met Amber.... And i honestly can't believe i never thought of this before, (apologies if someone else already has, but i didn't any other post's like this) But it is my belief that Penny isn't just a robot they made complex enough to generate an Aura. In the Vault Ironwood reveals Atlas has been experimenting with Aura, and that they made "Significant strides". Obviously the three of them are pretty sure it's going to at least work, even if it destroys Pyrrha's identity. How could they be so sure? I think it's because they already did a similar procedure when Penny was made. They took the Aura of someone else out, and put it inside Penny! Since Pyrrha is human, they would have no idea what would happen to her mind, but if nothing else they would know the transfer would work! So that's my Theory, Penny's personality was taken from a living host. Witch would also mean that said personality died with her. Even if they rebuilt a robot that looks like her, it wouldn't have the same personality because the person it was taken from is now dead. I know its kinda dark, especially for one of the happiest and brightest characters in the show, but i think it would make sense. Maybe Ozpin and friend's don't know exactly who or what Penny is, but Ironwood may have told them about the procedure to get them on bored with using it for Amber.