Terrain lighning problem(?)

I kind of don't understand what is going on with my terrain shadows.

FYI, I got generated terrain with nature->bumped specular material, and 4 procedurally assigned textures with normalmaps (through terrain toolkit). As a next step I added directional light, and shadows began getting wild...

Somewhere they look okay(wasn't fine-tuning the light, it's with default settings):

But when I change X-coordinate of directional light, it's getting wilder. When it's close to 0, shadows look somewhat like this:

I understand that every little bumpy (not meaning normalmap) thingy casts shadow, but, well, is there any way I can make this look good? Besides the fact that they're casted by every little detal of the terrain, they are very 'teary', so to say, all edgy... that's what I really don't like

And when I click create->directional light, terrain looks like it's lit from under the surface or something... very strange.

So, basically, summing up all I've said: Is there a way to make terrain's shadows look good, without tearing and 'patchiness'?