This may be of interest to the reader.

It’s a small info brochure from the first world war about the use of Stormtroopers that establishes a few modern principles like the two men Buddy Team.

The oldest troop type within the German military is the "Jäger"(Hunter), who were recruited out of the rural population like huntsman and foresters. First official Unit was raised in 1631. It’s basically a necessary approach when during that time in the 30 Years War there were armies roaming around and some of them highly mobile so much that it wasn't possible to mobilize regular troops to counter them with at first. So you raise these small Hunter Killer Units which entire purpose is sniping and harassing and sabotage. They were recruited exclusively out of the local population that today would be called something like a patriot, because many armies during that time were recruited out of foreigners with questionable loyalty.

Later the Hunter Units were also used as military police to Hunt Deserters. The British hired Hunter Units during the War for Independence to counter the American Ranger units. It also happened quite often that British and German mercenary troops used guerilla tactics against the Continental Army. Later the captured commander of the German Hunter Unit Johann von Ewald then visited West Point and 1785 published his book "Abhandlung über den kleinen Krieg"(Discourse about the small War), first written piece about battle tactics outside of regular battle array.

Also Ian Morris wrote in "War - what is it good for"

What the anthropologists rarely saw, because few of them could stick around long enough to see it, was that the real Stone Age fighting went on between battles. Battles, after all, are dangerous; anyone who stays put when the arrows fly, let alone runs up to enemies to hit them with a stone ax, stands to get hurt. How much safer to hide, then pounce on people who are not expecting it … which, anthropologists found, was exactly what twentieth-century Stone Age warriors liked to do. A handful of braves would slip into enemy territory. If they caught one or two men from the rival tribe alone, they would kill them; one or two women, they would rape them and drag them home. If they encountered groups big enough to fight back, they hid.

Even better than ambushes, though, were dawn raids, grisly episodes that crop up so often in the anthropological literature that habitual readers become numb to their horror. For a raid, a dozen or more warriors must creep all the way to an enemy village. It is nerve-racking work, and most ventures are abandoned before the killers even reach their destination. But if all goes well, the raiders get to their target during darkness and attack just as the sun rises. Even then, they normally manage to kill just one or two people (often men stepping out to urinate first thing in the morning) before panicking and running away.