I believe if this entire passage from, John is read it clearly suggests that Jesus, by His sacrifice, by His actions, had enabled a process to unfold. Part of this process was that Jesus would send a new Comforter. Now of course this new Comforter would be the same as Jesus in the sense that He would not speak of Himself and the Father would dwelleth in Him as well, just as the Father was in Moses and Abraham and Noah. So much so that it could be said that Jesus and this Comforter are one and the same, however they would not be the same literal body. The body of Jesus was a vehicle, no more than that, it was a human body that decayed after death as all bodies do and that body will never return.
You don't think it unlikely that Jesus would call Himself the Comforter and say that He would send Himself is a disassociated, third person context? Clearly Jesus is telling us that He will send somebody like Himself, only this time the message will be a full measure and this will fulfil the Jewish prophecies concerning the Messiah. I mean, there's no stretch here, you only have to read John with an open mind and accept what is being said.
