I've written about this meme before: my version of the time traveler going back with orders to kill baby Hitler is that, upon his return to his own time, he is put on trial for killing an innocent: having killed baby Hitler, there is no holocaust anymore either, so his crime has no justification. He himself has no evidence of being sent on this mission. His only vindication might come in having his own baby-self killed, thus negating his killing of baby Hitler but also re-instating the holocaust.
Imagine a person alive in 1900. Various people. They have no fucking clue about what will happen in the next 50 years of history. Nothing is foreseeable. It seem like it is, or should have been, because we know now what happened. They seem tragically blind to us. History explains why things happen, and gives an aura of inevitability to event, but this is an illusion: we can only explain because we know the outcomes already.
So the truest form of historical fiction would be science fiction. The only true test is whether we can predict the future, because prediction of the past is based on purely circular reasoning. We are tragically blind to what is about to happen, in the same position now as people 100 years ago.