I'm inclined to agree. If I was going to attempt this, I'd run the original image through something like the 'Watercolor' filter in Photoshop to turn the detail into large blobs of colour and then bring it into Illustrator, lock it, and draw over the top with the pen tool, restricting myself to approximating the shape of the blobs with triangles and picking the colours up from the original image with the eye-dropper.
Cheers
Jim