One could name dozens of different small causes that are important in themselves, and that could explain this state of affairs. However, I see one, you are afraid to voice as historians and archaeologists. Namely, as it is regrettable, but generally not archeology confirms historiography. Consider again the same example. Let's say we want to confirm the existence of the battle in a particular area, we start digging and find the fragments of a few arrows. It confirms whether it is the presence of a battle? If you do not think, yes. If you think about it, no, because if digging in other areas, where the battle was not, and there, too, we find fragments of arrows. For at a time when there were a bow and arrow, arrows fragments can be found in the whole area of ??their existence. Consequently, an archaeologist should not be easy to find a number of arrows, but the density of the findings of these fragments should substantially exceed the background density of the findings, that is, the density of finds in other areas. However, in some cases, this problem is not put by archaeologists, so just finding fragments of arrows though are some confirmation, but fragile.