I don't think it is really like that. Nobody is counting beans.
I'll be redundant:
You've got three ambulances, You can transport up to 12 patients. You've got 30 injured in a car accident.
Which ones do you take?
I'll explain it. You make three piles. Ones that are likely to live anyway, ones that are probably going to die or who are dead, and ones that you might be able to help.
The third group goes. It goes as fast as you can get it there. The other two stay on the pavement.
You have a better idea?
Yes. Find yourself another line of work.