I don't think it's that bad. Apparently this movie is looked on kind of fondly in Japan, despite the Hollywood-style historical inaccuracy.
Fun fact: Ken Watanabe's character is based on a historical figure, Saigo Takamori, who led a rebellion against the Meiji government in protest of the dissolution of the Samurai caste. In contrast to the movie, every contemporary depiction and account of Takamori's rebellion makes it clear that his army used modern weapons, and Takamori himself wore a French military uniform. So rather than trying to protect an endangered sacred culture or whatever, he was leading a reactionary insurrection against a land reform program.