It could be a prequel, with the story being based on Ancient times. A similar cataclysm occurs, forcing the continents of Europe and Asia together.

"Great Empire" faction - Ancient Roman warriors (centurion and legionnaires), Greek hoplites, Spartans, Macedonians

A Middle Eastern faction (Persians, egyptians)

A "barbarian" faction (Germanics, Celts etc)

Ancient Chinese faction

Being a history nerd, FH has to be my favourite fighting game of all time. Being able to fight as a historical warrior against other historical warriors (even if they did not have contact in real life) is a concept that is amazing. I'd love to see the same thing but with Ancient era warriors now. We all know how fun it is to play as Cent and Glad!