And with critical systems where the downside of any mistake is high cost, in life or money, it helps reduce risk if people only watch a small number of data poi

And with critical systems where the downside of any mistake is high cost, in life or money, it helps reduce risk if people only watch a small number of data points, which they can concentrate on fully. So, similar to your navy example, I have heard of early warning radar operators being asssigned to only 10 degrees of horizon on their screen, so you now need 18 people to cover east to west fully, but each person is completely focussed on their little task.