Now this is just my understanding of the scriptures and what I feel the Spirit has told me in regards to this title. Adam is a title like Elias is a title. The title of Adam is given to all Gods who come to a earth and dwell with lesser intelligences. Hence Paul calling ,Jesus, Adam. Now remember this is what the Spirit has told me, not what any leaders of the Church have declared.
When I studied Hebrew at BYU, I learned that the word "adam" is simply the Hebrew word for "man," and nothing more. If you want to consider that a title, then I guess that we are all Adams because we are all men.
As for Elden Watson, I read his article, and the reason his theory has not been widely accepted is that, as he, himself, admits, his interpretation does not explain all of Brigham Young's statements with regard to the Adam-God doctrine. In other words, nice try but no cigar.