It's not even that, it's plain goofy, but great fun when you like Von Daeniken, Illig, Hancock etc.
Right now Peter/Joseph/Juliana is posting the "reconstruction"drawing of the Caesar crucifixion around, so in case he will do so here as well and somebody might ask where it comes from, here is already my answer to that:
It was made for Carotta's own book and as goofy as the rest of it.
This is the basic idea of Carotta's book:
The story of Jesus is actually the story of Caesar rewritten (JC=JC).
Therefore everything in the Gospels must originate from the life of Caesar. Caesar was cremated, so Jesus must have been cremated too. And see: Carotta, that great linguistic genius, finds out that the greek verb 'stauro' doesn't actually means to crucify, but to put up posts or slets, and from there onwards to set up the cremation pile. Also the throwing of the dice over the clothes actually means throwing the clothes on top of the pile. (That we can find the origin of the dicepart in psalm 22 is a minor detail Carotta is not interested in). etc. etc. etc.
So that's almost the end of Jesus's crucifixion. But Christianity without a cross is even too much for Carotta, so after this brilliant tour de force he invents a Caesar crucifixion. To do this he combines different classical texts about Caesar's funeral in a ridiculous way. There was a lying wax figure of Caesar and there was a tropaeum, a construction to show his armour on. When you want to show such an armour you need a T-shaped construction and when you want to put a helmet on top, you have to give it a crossform; simple as that (In another forum a choose a modern cross shaped dressboy as my avatar, just to please Joseph, who calls himself Juliana in that one). But to Carotta this has a profound meaning. And since Jesus was hanging on a cross, the wax figure of Caesar also must have been hanging on that crossshaped tropaeum. (The obligatory similarities work in both directions, even if the results seem to exclude one another).
And there you have the background of this astonishing reconstruction.
So to recapitulate:
First we take the Caesar story litteral and adjust the gospel.
Then we take the gospel litteral and adjust the Caesar story.
Piece of cake.