The Chinese-centric ideology is far from Eurocentric, and they have instilled this ideology in their citizens as a more compelling belief. The nomadic Khitans and Jurchens conquered northern China (the Chinese gave them the names Liao, and Jin Dynasty?). Although the population indeed became a minority, the Chinese considered them to be their dynasties. Although the Mongols and Manchus occupied all of China and were a minority of the population, they were another successor and another dynasty of the Middle Kingdom, which is a strange expression of Sinocentrism.
Looking at the map, it is clear that the Japanese generals would not have chosen the area around the Khalkha River as their base, which is very inconvenient for the advance. From here to Ulaanbaatar, the waterless, uninhabited and roadless Gobi Desert stretches for nearly a thousand kilometers. The similar, deserted 700 km needs to be covered to the Soviet border. In addition, it was impossible for the Japanese to reach Soviet territory via the Khalkha River and Mongolia, given the difficulty of getting supplies for the poor Japanese army.