Without boring my readership I begin by noting the most glaring weakness in Doherty's hypothesis - his complete lack of support from ancient witnesses. No one interprets the Pauline material in the manner that he does. Indeed he seems utterly oblivious to the heretical exegesis of the very material he seeks to explain as - essentially - supporting their understanding about God. Indeed it is akin to arguing that the Pentateuch reflects the sacredness of Mount Gerizim without being aware of the Samaritan arguments developed in favor of this very proposition.
Why develop an argument for Jesus being supernatural without making an appeal to the ancients who held this very point of view? Indeed Doherty's assumptions about the relationship of Paul to the gospels are so banal you'd think he bought them out of a Sears catalog. As noted here before, the Marcionites assumed that Paul wrote the original gospel. To this end, basic underpinning of Doherty's arguments regarding the Pauline writings being 'unaware of the gospel' could well be the result of his dependence on a Catholic recension of scripture which did its best to deny the core Marcionite proposition regarding their apostle.
Some may argue that I spend too much time focused on the Marcionites. To this end it might be useful to provide an example from the Valentinian Gospel of Truth to demonstrate how Jesus was consistently as something other than the Logos - i.e. the 'power of the Logos.' From the opening words of the text:
The gospel of truth is joy to those who have received from the Father of truth the gift of knowing him by the power of the Logos, who has come from the Pleroma and who is in the thought and the mind of the Father; he it is who is called "the Savior," since that is the name of the work which he must do for the redemption of those who have not known the Father. For the name of the gospel is the manifestation of hope, since that is the discovery of those who seek him, because the All sought him from whom it had come forth. You see, the All had been inside of him, that illimitable, inconceivable one, who is better than every thought.
We could go through the entire document and demonstrate that again Jesus is not the Logos but the power of the word, the fruit of the true - however you want to describe it. All of which underscores the idea that it is the Logos which stays in heaven while this 'new power' Jesus becomes his presence on earth.