Actually, unifying all branches of the armed forces does not follow logically from the author’s argument. He clearly states that the USAF was originally a part of the ARMY and became a seperate branch after a desire to gain prestige.
In which he is pushing his own agenda. I'm certain that we would not be best served with the strategic nuclear mission and space missions under Army command (no bad on the Army, but these programs need their own focused approach).
I think the issue of whether the Army should have its own fixed wing attack aircraft is a good question.