But isn't the same thing true for computers? 10 CPUs running the same calculations will show variations in time, heat distribution, etc...
But the differences are all masked by the fact that the ten CPU's only produce different results if there is a bug or malfunction. When there is no bug or malfunction, the calculations generated as output should all be identical. And, I guess I should explicitly state certain qualifications (which I assume are implicit in your premise), such as that presumably the executed programs don't sample hardware registers for the purpose of random number generation, generally speaking that the state of external devices to which they attach are functionally identical (e.g., network drives appear the same when they are accessed by the different computers), etc. And we're talking about digital computers, as opposed to analog, right?
On the other hand, in the case of people, the idea that different people do different things when confronted with the same situation (in what they they choose
to do) isn't a bug; it's a feature and it's expected as normal variation.