Idea for an MMO "RACE WARS!!"

I thought of a story line for a multi-faction game set on Earth in the distant past.

apocalyptic time in the future some moon sized asteroid headed for Earth, everybody goin Die. blah,blah,blah

Man-kind has developed time travel, but they can't send people back to a time where they can change the past which would effect the future..yada,yada,yada..sometype of Back to the Future Paradox

So people are being sent 300 million years in the past to Pangaea (when all landmass was together)

As people end up there(no way to get back), they start noticing that the respective Races have certain allergic reactions to the plant life in certain areas but not others, and mix-breeds of people die off unable to cope and only the purest bred people of the respective races can migrate to the areas that are better suited for their respective races.

Fossil fuels hadn't yet formed(no gas, machines), and plant life while abundant, is new and mostly unknown as it either was extinct in the future or hadn't evolved into what it was known for. Same goes for animals.

That's the background setting, races=White, Black, Hispanic, Asian

Each area has protection from long term invasions(allergic exposures) but each area has unique plantlife/objects and whatever that the other areas need.

As the respective races start living on their new lands, they each develop untapped primal abilities that the new climate and diet bring forth.

And they war against each other because that's just what happens.

Typical wow style mmo....terribad?