Heroes 6 - Discussion

because it's not that easy – to just come up with a new race.

It depends on which one. In the case of the Nagas, it's as simple as it gets. Moreover, something similar (if not outright copied) was in the third Warcraft game in the add-on. Think about it, they took a race and simply adapted it to one of the cultures. They could have just as easily made them Indians. Zero creativity!