Without clear passages saying what you just said to that effect, that would be called philosophy, rather than scriptural doctrine. There's no mention of a "flesh son" vs. a "spirit son" so that part is of some man's devising.
Look to earlier than the account of his baptism, and you will see that the angels acknowledge him at his birth,
Luke 2:10-11 KJV
(10) And the angel said unto them, Fear not: for, behold, I bring you good tidings of great joy, which shall be to all people.
(11) For unto you is born this day in the city of David a Saviour, which is Christ the Lord.
But according to your earlier statement, it was not until the day of his baptism in which our Saviour, Christ the Lord, appeared. Also, Simeon did not see death until he had seen "the Lord's Christ" in Luke 2:30. Apparently Jesus was the Lord's Christ (the Messiah) from the day of his birth, not the day of his baptism. And according to Isaiah 9:6, the child that is born (not the man that is baptized) is He who shall be called Wonderful, Counsellor, the Mighty God, the Everlasting Father, the Prince of Peace.
Isaiah 9:6-7 KJV
(6) For unto us a child is born, unto us a son is given: and the government shall be upon his shoulder: and his name shall be called Wonderful, Counsellor, The mighty God, The everlasting Father, The Prince of Peace.
(7) Of the increase of his government and peace there shall be no end, upon the throne of David, and upon his kingdom, to order it, and to establish it with judgment and with justice from henceforth even for ever. The zeal of the LORD of hosts will perform this.
It doesn't make much sense to suppose that Isaiah means "his name shall be wrongly called" ... but rather "his name shall be correctly called."