I rather think it's plausible Jesus was a figurehead with the (already by then well established) messianic archetype applied to him who was hyped up by some Judeans as propaganda to incite their people to try to cast off their Roman rule. But then the notion really got out of hand some time after the original context was lost.

Given the prior number of Jewish prophets and messiah claimants (not to mention Apollonius of Tyana who also readily leaps to mind) there were probably several attempts at this, but only one made it to this level of popularity.