Juxtaposing the two stories–the young male Nazi soldier and the young female Russian flier–might seem like a standard approach, but it produces some unexpected things.
The German fears the Russians, who the reader sees most personified as this young woman. She’s cheerful, mostly chipper and very good at her job. Her comrades are similar, caring about each other; she even has a flirtation with her CO, who originally didn’t even like the idea of female fliers.
Among his countrymen, the young German doesn’t have anything similar. The Nazis only really bond at the idea of gang raping a Russian girl. They’re the invaders and the psychological wear and tear is worse on them.
Ennis introduced them as generally anti-Hitler the first issue (that standard storytelling device–the soldiers aren’t necessarily happy Nazis), but shows this issue it wouldn’t make them any worse as they’re already monsters. They’re just regular invading monsters.