Muddle me up, you did. :)
First I should say your use of “natural” man is a bit different, but..
“Natural man has the will to sin or not sin.” I don’t get your meaning here. Are you saying he has free will choices that include whether to sin or not sin?
Meaning those are his only choices. He has free will enough to choose from those two.
Saved man has three choices; sin, not sin, or do good works.