Usually you don't unwrap the highpoly, and when you do, they don't match the lowpoly at all. Just unwrap the highpoly as you want, it can be completely different, because you bake the details FROM the highpoly TO the lowpoly. Think you might have misunderstood how to make highpoly models to use for lowpoly.
Thank you McGreed for your reply. But to make things clear, I want to make the highpoly model look as good as possible, there will be no lowpoly version. I wanted to import the Turbosmoothed version of the object in Mudbox and paint over it. But because I unwrapped only the lowpoly object, and not the highpoly, this…