What matters is the divine institution of any given sacrament, and the signs are related to the grace, and to the divine command.

Melchizedek was a king - male. He was in the same category in Judaism with Elijah, the Messiah ben Joseph, and the Messiah ben David. All are described as being "without father and without mother, without descent, having neither beginning of days nor end of life, but made like unto the son of God abiding forever".

In short, he was a prefigure of Jesus Himself.

Jesus is not a gnostic genderless “body-soul” but an actual male human being. He did not die a genderless “body-soul” but died as human male.

The “body-soul” reference appears to be coming from the gnostic-theosophic literature as you are using it.

http://wn.rsarchive.org/Books/GA009/English/RSP1965/GA009_c01_4.html

http://theforbiddenreligion.com/body-soul-and-spirit.htm

But the Catholic Church teaches that Jesus was a man like us.