I think that as long as the characters are presented in such a way as to create the impression that they could’ve actually been there, it’s fine. Believeable and plausible characters raise the enjoyability of the story. The more plausible the character and situation, the better.
Of course, the more prominent a position, the less plausibility there will be due to their heightened status in history.
For instance, a secret lover of Hitler, close and intimate to the ruler, that nobody else knew about would be fine, but an Eva Braun clone, who fills her function in history etc. would not be. Even better would be if actual facts could be manipulated to make it seem as if it were entirely possible (like Dan Brown did.)
By this I mean, if for instance, there were actually records of Hitler going off to an unknown location in offical records etc. a writer could twist that into a premise that included a secret lover of Hitler and it would raise the story’s cachet. People would see it and enter reading already predisposed to believe it might be true or, at the least, plausible.
As far as Lt. Generals – this is a kinda iffy case, depending on the treatment. I’m not sure of the situation during WW2 but Lt. General is a pretty rarified rank. Also keep in mind that Lt. Generals are usually in charge of extremely large theatres of operations and so are far removed from the nitty gritty of day-to-day wartime/frontline operations. And they’re usually much older gentlemen.
Of course, the final solution is up to you, but it might be better to use a Watson solution. What I mean is - use a narrator of a lower, more common rank to show the higher ranked character – the way Doyle uses Watson to showcase Holmes. (Of course this may not be possible due to your story but it’s just a suggestion.)
I only say this because one of the allures of historical fiction is the realism. Readers like the sense of being in the shoes of someone who MIGHT’Ve actually been there and so they get an insider’s glimpse into actual events.
I think the closer a historical’s story is to real life, the more intriguing people will find it. The story in Titanic was obviously fiction but it fit perfectly within the structure of actual events. You were drawn into the fictive dream and could believe that it might’ve happened. You witnessed an actual historic event through the eyes of two people who might’ve really been there. If the writer's had used the Captain as the protagonist, I don't think it would have been as successful.
Another example of how a good blend of fact and fiction raises the intrigue factor of a story is The DaVinci Code. Actual facts and historical figures were used but distorted to fit within the frameowrk of the story. This made it seem so “possible” that some came to believe it might be true etc.
Ok, I'm rambling.
Good luck with your story, Ray.
