Should be entertaining even if saddled with what sounds like inane armchair psychology (maybe not unlike Phoenix's Joker in that regard). Hard to imagine a better actor for the role.

“Napoleon is a man I’ve always been fascinated by,” Scott told Deadline. “He came out of nowhere to rule everything — but all the while he was waging a romantic war with his adulterous wife Josephine. He conquered the world to try to win her love, and when he couldn’t, he conquered it to destroy her, and destroyed himself in the process.”
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The film’s title is derived from the saying “There is a general’s staff hidden in every soldier’s kitbag.” The film is an original and personal look at Napoleon’s origins and his swift, ruthless climb to emperor, viewed through the prism of his addictive and often volatile relationship with his wife and one true love, Josephine. The intention of the film is to capture Napoleon’s famous battles, relentless ambition and astounding strategic mind as an extraordinary military leader and war visionary.