I think 27 million is a fair estimate of Soviet casualties in WWII when you add in all the civilians that were killed by the Germans and the Soviets. Maybe half were soldiers, the rest were civilians. Elizabeth was correct when she told Paige that the Soviets defeated Germany on the Eastern Front, not the US/British allies who fought on the Western Front. The Soviets broke the German war effort and made it possible for the Allies to reclaim Europe from the Germans.

As for Claudia's 'I was at Stalingrad' comments...That actually makes me respect and understand Claudia. The assault on Stalingrad was the biggest, bloodiest and most deadly battle in modern warfare (maybe in all of human history). It's no wonder that Claudia became such a hardcore Soviet enforcer. Elizabeth was born and raised in the immediate aftermath of that war so it's understandable why she is also so dedicated to defending her country. But Paige has zero connection to Russia or these memories. Paige is sympathetic to the suffering that Claudia experienced because any rational, sensitive person would be sympathetic. But Paige will never be able to truly understand what Claudia experienced and she'll never feel the same zeal for the motherland that Claudia and Elizabeth do.