The worst thing about East Asian historical research

As expected, it seems to be the study of military history.
Whether it is because records regarding weaponry and killing were considered inauspicious and thus not kept, or due to the development of centralized systems, there are almost no detailed accounts of individual engagements or battles, which is quite frustrating...
While records regarding the lives of soldiers or administrative documents occasionally remain, it is a real shame that there is a lack of information on individual tactics or the mindsets and evaluations related to combat.
Even the surviving records are mostly exaggerated to strengthen the speaker's claims or are merely nominal (de facto), so there are pitfalls everywhere.
It has reached a point where people have to estimate battle hierarchies by looking at tomb murals or rely purely on archaeological excavations to make inferences.