That's simply not how movies work. There are a lot of things to take into consideration when trying to put a story that is rooted in history on the big screen. At the end of the day, it has to be cinematic while telling an engaging story. And it has to fit in 2-3 hours. You will never see anything that is going to be exact. In that case, it becomes a re-enactment, and real life is frequently not as straight forward as a 2 hour film can portray.
If you are holding out for a truly historically-accurate big budget multiplex epic, you will wait forever, because that will never happen.