>But also it provides a secondary check on the sensibility of the order.

For much the same reason, whenever there is an outage, I like to ensure my teams are running at least two people on the problem. When things are broken and you're trying to un-break them, having one person whose entire concentration is on doing the physical acts requires to un-break things and one person whose concentration is on monitoring things, looking up data, or reading through the SOP helps ensure things are done safely, that you have secondary checks on actions being taken and it also slows things down a little in the "slow is smooth, smooth is fast" sense.