The Viet Cong analogue is probably more relevant in Return of the Jedi, when the Ewoks fight the Stormtroopers. But even as regards the whole Original Trilogy, the “WW2 in space” analogy can only go so far (and refers mostly to the visuals and special effects), because the Original Trilogy is not about a war between political equals (despite the fact that A New Hope confusingly refers to a “Galactic Civil War” in the opening crawl). Rather, it is about asymmetric war between insurgents and an all-powerful totalitarian regime.