As for non sequitur's, sloppy or not is irrelevant. This argument has been going around endlessly, so to speak, because nobody has the facts, there is then no original premise to go sloppy on, nor any logical conclusion.
As long as that "I" is not connected with any objective form, now Jesus and me can both say this same "I"....which applies to all, male or female, black or white. This "I" does not discriminate. I can only insist I have no objective existence, as some may imagine "me" to be. Hence in my very absence and non action, all things are made for me. Yes I have an appearance which is conceptual, but that does not establish any eternal reality as such, being born and then dying. The accusative of "I" can only be "you", for "me" would be a non sequitur, self contradictory, because these objectives such as "you" or "me," is always the only subject "I", and such is the metaphysical truth, that "I" being nothing, is also everything...all objects or forms. That applies equally to Jesus if he existed or not, and all of us.
The real question is do "you" exist? If all of us have only a conceptual existence in mind? Do we not all come out of matter, is gold no longer "gold" when it become a ring or an artefact? So this "historical Jesus" is just as conceptual, as "you" or "me"...or agent "Smith" in the Matrix movie.