“羸兵”可以翻譯為：

1. **Weakened troops**
2. **Exhausted soldiers**
3. **Fatigued forces**

具體選擇需結合語境。若指因饑餓、疾病而虛弱，可用 **emaciated troops**；若強調疲憊不堪，則用 **exhausted soldiers** 更貼切。例如：
> “敵軍久戰乏糧，已成羸兵?！?
> “The enemy, after prolonged battles and food shortages, has been reduced to **emaciated troops**.”

需要進一步優化的話，我隨時可以協助。