(1º)An history is technically incorrect it should be a history but an before a H is becoming more of a normal choice so I haven’t corrected it. Please bear this in mind though if you ever do a test. (2º) you have changed tense it can all be written in the present tense. (3º) I am having difficulty understanding your meaning but I think you are saying the context of the story is correct but not the facts. The were mistakes with the time periods of events and also with the manner in which they used the weapons.