For example, Kenkokuki's chapters 40.1 - 41.1 have the exact same conflict, character, development, etc as Oukoku's chapter 73. (Link below)
Maybe this is just one big coincidence, but after I noticed it once, I started noticing repeats of certain events over and over so I figured I had to say something somewhere.
Both novels had their chapters written in a relatively close time period. But technically speaking, if someone is guilty of "borrowing material", it would have to be Kenkokuki based on release dates. If someone wants dig into this deeper, be my guest.
https://lightnovelstranslations.com/road-to-kingdom/chapter-73-treia-conflict-%E2%91%A0-hill-of-grief/