What happen often in force on force is that once searching for the opponent, individuals who fully raise their weapons are either prematurely shoot on the opponent as they skip PID, or lower the gun in order to see and shortly afterward raise up and then shoot – which actually, and most ironically, increase the time of response. An individual who is already at a proper and logical lower ready position can already PID and in the process, almost at the same time, already bring up the gun – and shoot.
One remarkable development is for sure the firearm. This changed the battlefield forever and melee combat lost it´s relevance more and more. Even here you can see the change from the formations of line-infantry to ranger units (Jäger, Chausser, etc.) as the rifles were becoming more precise, reliable and cadence increased. Now we are in the present and the state of the art in infantry tactics are SOF, starting to develop in WW II. When Skorzenzy had nothing than a bunch of daring men (of course battle-hardened then), a Jaegerkorps soldiers schedule might be very down to the point until he is ready for deployment. Again humans want to structure their world.
Within the tactical- and self-defense community the discussion of experience over practical training is often a hot topic. With any sort of training aid the question also arises: What background does it derive from? Which is a total legit question to ask.