The entire Guccifer narrative is the most speculative and least substantiated aspect of the entire drama. That doesn't mean it's false, however.
But one might wonder why anyone cares about it or gives it any consideration, when there are so many far stronger data points.
The Guccifer narrative supports (weakly) the idea of a link between Russia and the emails.
So in order for this to matter you have to believe that Russia matters when considering WL.
And in order to believe that you must believe that WL's journalism does not stand on its own and that the motives of those who leaked information are what matter.
But WL is designed to be immune to the ill effects of specific political motives for releasing data. I'll point out some of the many ways:
- WL tries to verify that it is being given authentic documents. Revelations that documents WL publishes were inauthentic would sink WL nearly instantly. So authenticity absolutely must be the #1 consideration.
- For any leak there is an entity whose data was leaked. If a leaker doctored information before sending it to WL, the leaker could easily be discredited by a public release by the entity of an authentic version, revealing what had been doctored, which would reveal motives.
- WL insists upon full, unredacted documents. Most of the leaked information has been mostly irrelevant. You could spend days reading WL releases without encountering anything juicy. Why? Because the full documents provide evidence that no aspect of the document has been withheld to create a false impression. This results in a lot of boring stuff -- most of the HRC emails were bulk mail sent to the addresses in question -- but lets the legitimately interesting data stand in proper relief without suspicion.
- When possible, WL goes to great lengths to validate/authenticate data. WL created a tool to allow site visitors to easily validate the DKIM/DomainKeys signatures validating that the emails were unmodified. If salacious or newsworthy information had come from an email that failed DKIM/DomainKeys verification, WL's approach would make that obvious even to those who do not understand how content signatures work.
- WL can be weaponized by anyone against anyone. There was a US Army report identifying this characteristic early on. Falsifying the identity of leakers would of course be a valuable tactic to use when weaponizing. WL is useful because of the aforementioned characteristics and in spite of being able to be weaponized in this way. It's not novel that a government could submit intel obtained by its intelligence agency to WL to cause a political consequence in another nation. Of course this could happen. It can even be done by domestic parties like Chelsea Manning. It's a question of whether the information leaked is beneficial by providing important transparency or revealing outright fraud/crimes.
I have to wonder when people oppose Assange due to indignation about Russia or Manning if the underlying reason is actually that they don't view the war logs or the emails to have been useful investigative journalism.