Texture and foliage don't fit

I am having a landscape and I am trying to create some variation by using a noise texture to mix two color textures. (Fig. 1)
All textures are world aligned because I want to add static meshes with seemless texturing to the landscape.
That works fine so far.

But when I add foliage (Fig. 2), I want the distribution to be aligned to the texture. Meaning, I want to have the foliage corresponding to the textures.
And there are the problems coming. (Fig. 3)
The foliage is somehow distributed with a mask, but it doesn’t fit with the textures.

When I am using Texture Coordinates or Landscape Layer Coords, the textures fit perfectly to the foliage. But with these I can’t mix Static Meshes with seemless texturing.
And I need texturemapping on vertical cliffs, too.

Thank you in advance