I don’t know if you’ll take this. Field Marshall Friedrich Paulus sort of, as he also fits a defector. As in he surrendered, was imprisoned by the Soviets, and then became big into East Germany.
He fits because he didn’t just surrender, but disobeyed an order from Hitler to die fighting or kill himself (famous (mis)quote: “I have no intention of shooting myself for this Bohemian corporal,” mocking Hitler’s military service). And ordered his men to disobey orders. He had no way of knowing what would happen next and weren’t there a lot of horror stories about surrendering to the Soviets? So not exactly expecting to side with the winner.