We do not know if hercules was based on a real person or not
Congratulations. You've shown that we don't know things nobody who has the faintest idea what historiography consists of believes we do know. Moving beyond the blindingly obvious, we can look to historical research and historiography as they are actually practiced and conceived. Doing so, we find that all arguments are limited as "best explanations", and in fact this is the foundation of the sciences as well as the humanities. What you are essentially arguing is that because inference to the best explanation is the basis for thinking Jesus historical, this matters in some way that somehow doesn't extend to everything from evolutionary theory to quantum mechanics. Hell, most of modern physics is actually developed, formulated, and represented in terms of information theory.
Can I then take it that you agree that the historicity of Jesus is an inference to the best explanation, and that is abductive reasoning?
"A hundred years ago, Charles Sanders Peirce [1931-1958] coined the concept of abduction in order to illustrate that the process of scientific discovery is not irrational and that a methodology of discovery is possible. Peirce interpreted abduction essentially as an inferential creative process of generating a new explanatory hypothesis....Abduction is the process of inferring certain facts and/or laws and hypotheses that render some sentences plausible, that explain (and also sometimes discover) some (eventually new) phenomenon or observation; it is the process of reasoning in which explanatory hypotheses are formed and evaluated."
Magnani, L. (2009). Abductive Cognition: The Epistemological and Eco-Cognitive Dimensions of Hypothetical Reasoning (Cognitive Systems Monographs, Vol. 3).