Before you abandon the idea, I think that it would depend on how much you intend to cut out. There are definitely methods of rendering images, like v-carving, that would leave plenty of surface for the sled to ride on. Another method is cone shaped depressions of differing depth
https://www.instructables.com/id/Engraving-an-Image-With-a-CNC-Router/
As for the detail, that would depend on how dialed in you can get your machine.
Here’s a good posting of some detailed artwork:
and that with a stock Maslow without many of the later improvements considered essential now