Hello everyone, I've made a guide based on my experiences completing Humankind on it's highest difficulty setting. It is pretty in depth and goes through the eras step by step. It is located here: 

https://steamcommunity.com/sharedfiles/filedetails/?id=2589034832

I'm hoping that I can spark some discussion with it and hopefully help those who are achievement hunting for the two that require Humankind Difficulty to achieve.