The prefabs.xml decides where the poi's go, so the EASIEST (but time consuming) is to go into the game, find a coordinate you want a poi to spawn from (F3), and edit the prefabs.xml to match.
...facing north, prefabs will/should spawn to the NORTHEAST from that point, meaning that if you stand on 0,0,0, the prefab will spawn starting from the lower left corner to the upper right corner from 0,0,0. I haven't actually tried it yet, but that's how it worked in previous versions.
Stand at the yellow X, and the prefab will spawn as such: