Why is the car in chess called "Ju"?

In the Zhou Dynasty, riding was actually a vehicle (residence) consisting of 75 soldiers and a chariot. Three of them are in the car, one is the driver, the other is the leader, and the other is the archer on the left. This group is called Che (Ju). If the people in the car are killed or can't move, the ones behind them will be connected. Soldiers before the Warring States period were all nobles' children. They must receive military training, riding, shooting, fencing and riding, and they must also learn military affairs. People engaged in agriculture can't be soldiers.