You can. However, Taleworlds didn't and don't recommend it. The scene editor can't sculpt the fine water erosion and weathering channels, which they created in Houdini. World Machine can provide similar erosion. If you sculpt your worldmap in the scene editor, you will probably need to export its heightmap to an external software package to produce comparable results to Calradia's main_map.
Okay, thanks for the info, will look into it