If you clicked on the link above you can see what a difference adding the filler has made. I bought brown wood filler as an experiment to see as and when the terrain takes a knock whether it helps with reducing white chips.
As a note. these are 10mm scale building from the now defunct Fieldworks range of resin buildings. However, in my considered opinion or perhaps experience, I find that they work with 15mm figures too.
So the next step is to add Woodland Scenic ground foam.