You looking for an outpost or just a wandering group? As both of those can only spawn in biomes that can spawn villages, for example, they can spawn in deserts, plains, and taigas, but not in jungles, swamps, or mushroom islands. I've got a hardcore world and they won't stop spawning around my base (it's this really cool generation thing where the spawn chunks is a strip of chunk errors surrounded by a giant desert).