The correct answer to this open question is the following.
I agree with the idea that says that The soldiers at the Somme were 'Lions led by Donkeys'.
We are talking about one of the battles in the western front of World War I, the Battle of the Somme that started in July 1916 and ended in November, the same year.
The British army was known to be a fierce and experience army, full of brave English men that wanted to defend their country. They were the lions in this metaphor. On the other hand, the military leaders that commanded the British army were not at the high level of expectations to lead those brave troops. That is why they called the donkeys.
At the end of the battle in November, the British Infantry suffered many losses. It was a nightmare. According to historians, the English troops suffered approximately 57,000 casualties. during the three months of the battle.