Hi Nil,
Yes, that sounds right to me. You seem to be saying that "larger sets are easier to describe", which might typically be the case. I can think of one counter-example:
Imagine a star-shaped set, or maybe some complicated fractal set -- say, the mandelbrot set. Several circles lie inside the mandelbrot set -- they are subsets, they are simple, easy to describe. But also, the mandelbrot set also lies inside of several circles - again, the circles are easy to describe.
I cannot find any convincing variant of this example in the "universe of physical objects"