After looking at them for a while, I decided to apply a dark wash overthe rocks, dirt, and the feet of the figures, so that where they met the grass, they would become more defined. This also brought out more colour in the rocks and dirt patches, making them more visible, which I think I like. (sorry for the slight blurriness in the photo)
and a low photo. I think it looks less like the figures are attached to plastic circles now :) It's a pity there is still a very slight rise around the base edges, meaning a line of shadow circles it. I was hoping the grass would touch and 'blend in' with the table top.