Well, here it is.
If you accept X, Y and Z as assumptions in your analysis, then yes, the draft is unconstitutional. If you accept R, S and T it is constitutional.
We are not dealing with something objective as such. We are dealing with a social construct and how we interpret it is also a social construct.
There are no scientific natural law/theory of the Constitution and no objective methodology for how to interpret it.
I have no desire to play a game of my assumptions are correct and your aren't. It can't be done. It is a case of limited cognitive, moral and cultural relativism and ends in this: Man is the measure of all things: of the things that are, that they are, of the things that are not, that they are not." Measure is the social, value evaluation and all that.