I don't think the mental-asylum Jesuses believe that they live in Jesus' time, so no contradiction with 18th century math arises.
Well, if the Jesus of the story is reasoning from the evidence favoring his being the first Jesus, the position is going to take a substantial hit.
Yvain isn't a big enough self-promoter to link to this, but I liked it a lot and I think you will too.
"The Last Temptation of Christ"