Well, the guy has sent me a small picture (not anything even semi good yet...) with a few placeholders (trees) and a couple rocks...



He whipped that up in about 20 minutes...

So mostly everything will be to scale with the trees. Buildings will be about 3/4 of the size of the upper left tree, and the person will be about as big as the small rock... (the upper left rock)

And a small picture with a person in it: