I'd say maybe reduce the contrast in the texture, and leave it for the smaller structures. Then either devise a new, bigger texture for the walls or double-size it (although the former would probably look best.) Trying a less blocky texture would probably work well for both small and large as well. Example: see Arid Canyon. Textures are very flat and large but work well on big surfaces because of that. Save the detailed textures for the detailed structures.