the wc3 models look waaay out of place against those timber things especially
it doesn't look very dirty? you should probably try somehow staining the walls, ie smoke smudges or some other thing like that, otherwise i'd try somehow varying the walls in some way - they're all rather uniform and that doesn't help to remove a clean, orderly feeling
i would stick to one kind of wood - the super high res from ogre as the timber bars look really cool but then the rather good looking barrels look really bad against it, it just kind of throws it out of balance and removes a much better feeling that you could have
beeches? really? i'd try little bushes or something, but beeches are a pretty clean looking tree - the white bark does it, the little, orderly leaves. and also, even small trees would be rather rare in a slum area, bushes or scrubby things would be more fitting
but really all in all its pretty nice