In both China and Egypt the nomadic people brought new culture to each society. Mainly they brought cultural diffusion to each. From each place the nomads traveled from, apiece of that culture got incorporated into China and Egypt, bringing new ideas, and improving society. Chariots were also a similarity that the nomads brought to both China and Egypt. Mainly nobles, and the military used the chariot as a way of transportation. The chariot was a way of showing social hierarchy, and also improved warfare tactics. These similarities greatly impacted and improved the great societies of China and Egypt.
The effects of the nomads and their incursions on China and Egypt differed in many ways. The Chinese living near the Yellow River had to become nomadic due to agricultural reasons, while in Egypt the nomadic life style was forced upon them by being forced out of their homes. Due to the Chinese becoming nomadic because of agricultural reasons, many issues formed between the non-nomadic Chinese people and the nomadic Chinese people.
So for 2,000 years the nomads harassed, invaded, and even conquered the settled agricultural civilizations of the Chinese empire causing many incursions. Counter to that the nomad people helped flourish the Egyptian life style along the Nile, raising its population tremendously. Lastly one other difference of the effect of nomadic people and their incursions on both Egypt and China was, in China the nomadic people concentrated on herding their animals, and in Egypt not so much.
I think the differences between the way the nomads affected China and Egypt were do to the way the different empires were run. The governments were ran differently, there for making it tough for the similar attributes the nomads brought, making it hard to affect them both in the same way. In the end weather the affect of the nomads and their incursions were similar in both China and Egypt or different, those attributes that were brought to the societies by the nomads helped form those two top regions today.