Yeah, I suppose, but for me talking about my essential characters, it matters to me enough to consider them different. If you want us to go with a generic single Vader for this theoretical line, then I'd have to change my ANH vote since ANH ain't my "generic Vader" look.
At least all of the versions of Vader pretty much look the same to the average person. There is quite a bit more difference between all of the different versions of Luke from all the films. I would be happy with one version of Vader, even if it does not match the movie on the card. In fact, this theoretical line may just say "Star Wars" and not indicate a specific movie on the card.