Readable and fun, but this story does follow a lot of tropes. Criticisms based on that are valid, imo. That said, it's fun enough to where I wouldn't mind seeing more. Almost everything's based off of something else. Heck, we even have manga based on classical art and anthropomorphized countries and such.
That and everyone ripping of public domain works like Robin Hood and Sherlock Holmes, along with various warring states histories (every country seems to have a 3 kingdom or warring states period honestly).