Are all CAM software and file types the same as far as precision work is concerned?
Obviously STL files are no good for precision work if it involves a lot of round or circular features since they are faceted and it will be milled as such even with a high mesh density, whereas other filetypes or CAM software may allow proper arc interpolation so the circle is at least as good as possible?
Maybe you are confusing several different terms: Accuracy, precision, detail, and complexity.
STL is not the best file format for true arcs as you indicate. Some CAM software will approximate arcs for the best fit.
What are you actually trying to accomplish?