Yes, I read the wiki on Samurai as well. Nothing there lead me to believe, during the time period of the first game or this new one, Samurai were anything more than landed noble males set up to administrate fiefdoms and be called to war when their lord requests it, along with their lesser unlanded nobles (retinues), just like European Knights (nobility). That is not a job that would ever be given to women, just because of how the social structure works. It even seems easier for Japanese lords to take away lands from lesser samurai under them and give it to another. Just like Europe, I would guess that large fiefdoms and titles may have had women "ruling" the fiefdom while their son comes of age, but that's about it.
I'm not a weeb and could give a fuck about Japanese media (other than Kurosawa, peace be upon him). In fact I dislike the vast majority of the Japanese made games I tried playing and am very particular about the anime I have seen. I also found the first Ghost game to be mediocre and quit after the first castle (freeing the father). Still, I am interested in history and misrepresenting history pisses all over everyone, including the people who "suffered" through the ridged social structures imposed upon them.
If you want to learn about Japan's misadventure into Korea
HERE is a good video on it; no need to wait/rely on movies or games to change things for artistic reasons.
HERE is a short one on the Mongol's misadventures in Japan and
HERE is a short one on Nobunaga, which is slightly before this new game is to take place. Also, here are three 20 min videos focusing on battles Nobunaga fought:
HERE,
HERE, and
HERE.