I cannot figure out which version of this sentence sounds better.
After Cortés’s army had been surrounded by Montezuma’s soldiers, this alliance turned out to be critical to Cortés’ victory.
Or
After Cortés’s army was surrounded by Montezuma’s soldiers, this alliance turned out to be critical to Cortés’ victory
I understand that 'had been surrounded' is pluperfect so it happens further in the past. This seems to create a nice contrast between 'surrounded' and 'turned out to be.' However, I'm not really sure which version of the sentence sounds better.