What tactics did Li Mu and Meng Tian use when they fought the Huns? What is the difference? Tell me in detail.

Personally, I feel that the mobile warfare used by Li Mu in the Xiongnu War was a diversion, with the cooperation of various services and arms (cavalry, string control, etc. Meng Tian, it was Qin Jun's powerful crossbow that made the Huns dare not commit crimes in the south. According to research, Qin Jun's strong crossbow can shoot 300 meters away. So personally, I think Meng Tian relies on its equipment superiority. In addition, Li Mu has taken the initiative to attack, and Meng Tian is basically defending. That's basically it.