A core element of the Battle Brothers setting is that regular humans, not even necessarily ones with fighting experience, have to overcome challenges with the means available to them. There are no over-the-top attacks for your Battle Brothers, like your archer shooting 3 arrows at once, just those you could realistically pull off with a real medieval weapon. Sometimes those guys happen to have to fight non-humans or even supernatural foes, which makes for even more of a challenge. This asymmetry between your regular humans, limited by what a human can do, and, for example, a necromancer wielding dark magic, is very much intended; your enemies should feel special, alien to a degree. It’s a great ingredient to many a horror movie and key to the atmosphere we want to build. But it would get lost in your run-of-the-mill fantasy mishmash if your guys started flinging fireballs or were, in fact, Elves or Dwarfs themselves.
That being said, if we get the opportunity, we’d love to expand the world with other human cultures eventually, e.g. one based on medieval Arabia – including weapons and armor of that area, unique cultural backgrounds for your characters, etc.