What is the biggest problem of ethnic integration in the Western Zhou Dynasty?

The biggest problem faced by ethnic integration in the Western Zhou Dynasty is the problem of adherents of Yin and Shang Dynasties.

At the beginning of the establishment of the Western Zhou Dynasty, it was faced with the problem of adherents of the Shang Dynasty. In order to appease the adherents of Shang Dynasty, the Western Zhou took a series of measures. First of all, Wu Geng, the son of Zhou Xin, the emperor of Shang Dynasty, was establishing political power, respecting Shang Dynasty as the capital of Yin, and naming the capital of Yin as the east, west and north. This arrangement aims at preserving the tradition and culture of Shang Dynasty and endowing the adherents of Shang Dynasty with certain status and power. In addition, the Western Zhou Dynasty also ordered Guan, Cai and Huo to supervise Yindu, in order to prevent the pro-business princes and merchants from rebelling. These measures are aimed at calming the dissatisfaction of the adherents of Yin Shang Dynasty and promoting national integration.