Was there an answer to my question in all that? You clarified that you don't mean the NT writers lied, but then you didn't address the question of why the writers told the same stories, whether lies or something else.
It doesn't matter to me why
these 'stories' (keyword) sound similar. They are not historically reliable (as they are filled with inconsistencies, contradictions, borrowed stories and errors). The Barabas story for example is clearly a myth (see video below) and the dying/rising god narrative isn't new at all. It existed in lots of other pagan myths prior to Christianity. This emulates precisely what we see in other man-made false religions. But there are any number of possibilities that could explain the similarities, none of which require the amount of assumptions you are making (for example one writer could have started it, maybe Mark, and then the others just copied off of him or subsequent copies). To merely assume their accounts are true a priori is to display an absurd (and hypocritical) standard of evidence.
-worldwide darkness over everything for three hours
-zombies of corpses getting up out of the grave and walking around Jerusalem
-alleged ground breaking/rock splitting earthquake
-Barabas (a fictional character in Luke with a fake name) claimed to be the prisoner allowed to escape
-The Jesus/Cleopas story (mimicking the Roman Romulus/Proculus story)
-The parabolic story of "Lazarus" in Luke (who won't convince anyone), changing to a 'real' Lazarus in John rising from the dead (to convince people)
Historical narratives do not make these kinds of claims. They do not have these kinds of symbols, parables, and metaphors. Myths and mythology do. And we have ZERO (0) contemporary historical accounts of any of it. Funny huh? Thus, we cannot trust them (just like we cannot trust the other man-made fictions of old to be reliable sources of history) and the fact that you would believe and defend them shows your bias toward confirmation, from the a priori assumption that they are stating fact. Again, it is gullibility to just believe textual accounts of the miraculous and supernatural, and this is again quite characteristic of credulity throughout the world religions (ancient and modern).
Textual claims to the miraculous cannot, do not, and will not confirm the miraculous because they are unreliable. Men throughout history have, over and again, made up false stories, embellished, exaggerated, plagiarized, and copied credulous hear-say for far too long (and far too wide) to place trust in them (see Islam, Mormonism, and countless others). Extraordinary claims require extraordinary evidence and we simply do not even have ordinary evidence for such claims in the bible. Thus we shouldn't place any trust in such claims.