IMO, given that most here aren't going to be messing around with IV fluids and making decisions on blood transfusions the effective take-away, the lesson that can be put to practical use, is to apply tourniquet/s early. If the bleeding from a wound isn't obviously insignificant you skip the direct-pressure and pressure point steps taught thirty years ago and apply a tourniquet. When things slow down you come back and reevaluate.

It is simple enough, but often quite painful, to remove a tourniquet that was installed where it wasn't needed. Putting blood lost back in is a much harder trick.