Heroica does use inspiration from real history, real nations and real ethnic groups. Sometimes this inspiration is factual, sometimes it's based on stereotypes, but it is only included because it made for interesting roleplaying fuel, and it in no way reflects back on anything in the real world.
Likewise, there are almost no pure "bad guy races" or "evil races", and the few that exist are entirely mythological. In general, the goodness or badness of people is based on their actions, not their ethnicity. Their victims, however, may be selected based on ethnicity.
Heroica is a rough world. It does contain a lot which is considered bad by any civilized standard. Slavery, prejudice, oppression, violence as entertainment and so on. This is to create a world with conflicts, where there are challenges to overcome and bad stuff to fight against. Utopia is not a place of excitement and adventure. Once again, this does not reflect back on the real world. If women can't be knights in some place, or shamans can't be men in another place, or non-humans will be seen as things which are only fit to fight in the arena, or poor villages are seen as a place to raid for slaves, it's not because it's the way it should be. It is because that's the way it currently is, and it creates problems which the players need to solve, and issues which the players may need to fix.
So, it's a rough, unfair and cruel world. You can make it better. Are you up to the challenge? Will you be the hero?