I've worked on Smutbase models before. You could do two ways to get the textures, you can go to Texture Paint and save every texture you can find on there that way going down one by one or (if its missing PNG textures and its mostly just colors) you can bake the nodes into a PNG texture. Sometimes it works, sometimes it doesn't.
But that's how I personally get textures. Or just make my own if I'm feeling really lazy.
Hi! Unity automatically converts all polygons to triangles. This means any polygon shape is split into multiple triangles. Unity may also need to duplicate vertices for specific rendering calculations like smoothing groups or UV seams. So your triangle count will always be higher in unity than blender.
As for your humanoid issue, could you explain further?
