What is the theme of the feudal system and the county system in the Western Zhou Dynasty?

I don’t know what topic you are talking about and what you are asking about. I'll just talk about it casually

In the early years of the Western Zhou Dynasty, the Shang Dynasty was destroyed through sneak attacks, but its own strength was very weak and it was impossible to control the vast area originally controlled by the Shang Dynasty. Once the Yin and Shang forces were concentrated, it would bring big trouble to the Zhou Dynasty (the Rebellion of the Three Supervisors). Zhou had no choice but to send his own troops to establish many small colonies on the territory of the Shang Dynasty in an attempt to prevent the alliance of Yin and Shang forces. This is the background of feudalism. Enfeoffment was a good system in the early days, because each feudal country only had one city, and the city was surrounded by local indigenous people, who often had a hostile relationship with the feudal country. The feudal country could barely survive and had to rely on the central government, let alone try to challenge the central government. At the same time, because of the existence of the feudal state, the military pressure on the Zhou Dynasty was greatly reduced, and there was no need to worry about the counterattack of the Yin and Shang forces.

By the time of the Eastern Zhou Dynasty, the power of the Yin and Shang Dynasties had already collapsed and the indigenous residents had been assimilated. Due to the development of productive forces and the increase in population, the power of feudal countries became stronger. At the same time, the enemy's weakening allowed the feudal state to start thinking about strengthening itself. The feudal states began to build cities everywhere and annexed each other. When it becomes powerful enough, the feudal state can challenge the emperor. This is the end of the feudal system.

The feudal state itself also developed some methods of controlling cities, which is the county system. Later, the county system was developed. The county system is suitable for countries with relatively developed productivity and less internal and external threats. Developed productivity allows the central government to strictly control counties, while smaller internal and external threats make local government itself the first target that the central government must be wary of. The constant replacement of local governors prevents local governments from forming close ties and therefore being unable to challenge the central government.