Remember, however, that all academic disciplines adopt particular ways of expression and forms of writing to best communicate their special subjects and separate themselves from others. Today, historical writing reflects efforts within most institutions to do away with sexist language and would now demand that any reference to a mixed collective, real or hypothetical, not be sexually specific. While historical conventions may come and go, they do so slowly. Just look at documentation styles. And while some history instructors will now accept different documentation systems, such as the MLA or the APA styles, many more will not.
History is a complex, changing discipline and historians are a diverse group.
Even so, most history instructors agree on the critical importance of written communication in the field. Since your instructor will pay close attention to your writing, your attempts to learn and follow these conventions will be noticed and will be worth the effort. People in the past were not necessarily less intelligent, more cruel or less insightful than we are today. The study of history encourages a certain degree of generalization, but don't overdo it. But such problems in history writing are usually more subtle, and often involve negatively judging those in the past by our present day ideological or technological standards and experiences.