In The Worlds in my Head the humans have taken to the stars five thousand years ago. Mother Terra is still thriving, but it is no longer Home. Instead, humanity is spread across as many star systems as there are real-world nations on earth, each with its own histories, traditions, and spiderweb of politics. In general though, they are allied with the Silmn (but not always), fighting the First Ones (but not always) and if you ask ten governments about the Nathi you will get 83 distinct opinions.
This is a Human planetary marines force somewhere in the galactic sector where all four factions have claims, and display implementations of borrowed technology from all of them.
Figures by Khurasan Miniatures.