So after some searching, I found changing the blend mode to "Masked" and plugging the alpha into "Opacity Mask" seems to have fixed this. Is by you saying "opacity mask" meaning what I mentioned above?
There are strange problems with landscapes as of recent, do you notice how there is a faint blue checker square like that of the default material? Something strange is going on with how it is blending layers or how you have the chunks split.
Here is the Life Planet graph: I actually didn't use a whole lot of noise filters just mainly blending main parts of the planet. The most filters I used is up above, the Machine Planet.
I'd suggest an alternative to @Apocrs1980, and that's the newer volumetric fog controls: https://docs.unrealengine.com/en-us/Engine/Rendering/LightingAndShadows/VolumetricFog No alpha blending worries and full lighting interaction, depending on your lighting setup.
Ok, fixed the problem with the alphas. The fog was messing up the lighting on them, so all i needed to do was take off the fog option in the material setup as it's using a translucent blend mode for the soft edges.
You don't have to over complicate things, a pretty much flat building is a pretty much flat building. blending between 2 or more textures is definitely the way to add detail and avoid obvious tiling.
The creepiness is what makes it great! Keep the contrast. But I agree with X-One that blending the face and rock together would make it look more like a baby golem and less like a baby in a golem suit.
It looks really solid, and I like the lighting. The only thing I would suggest is to add some vertex blended dirt, moss or colour variation to break the walls up a little bit. Good work!
Doing a unique high-polygon of every building is going to get prohibitively time consuming and resource intensive. Try looking into creating a shader that lets you use vertex color to blend damaged and undamaged areas.
The color version of tile sampler etc support alpha blending, this will help with overlapping. To get that sort of distribution you're going to need to use several tile samplers/tile random nodes and composite them together.