Honestly, drop the american white guilt.
Study the cultures, learn what you can and make the system based on what you learned. You are not making a fantasy RPG based on the history of a country and RPG fans will look for great writing and great game mechanics, not a 100% precise cultural demonstration. I have seen some elements from my culture in a few games and never gave a fuck if they were precise or not.
If my word is not enough, learn from the most successful RPG series of the world, Final Fantasy. It was made by a Japanese team and their settings, spell and weapons take a little from several places in the world, not only Japan. People don't love their games because Shiva is a great representation of the Indian culture.