It’s so odd to me that anybody is putting much thought into this without knowing what the narrative purpose of the choice is. Take shogun, for example - this has a British protagonist (although arguably Mariko is the protagonist). But this serves a strong narrative purpose - at the very least, it is a convenient (albeit common) device which allows you to spell out the culture, background, etc. for the audience under the auspices of that stuff being told to the character who is also unfamiliar with it. And from a plot perspective, that white character also helps fill out the christianization of Japan subplot.
It could very well be the same with AC. That they picked a black samurai outsider could be a relevant plot point. That it is this one in particular - who had close contact with Nobunaga - may also be central to the plot and story they want to tell.
It’s so odd to me that anybody is putting much thought into this without knowing what the narrative purpose of the choice is. Take shogun, for example - this has a British protagonist (although arguably Mariko is the protagonist). But this serves a strong narrative purpose - at the very least, it is a convenient (albeit common) device which allows you to spell out the culture, background, etc. for the audience under the auspices of that stuff being told to the character who is also unfamiliar with it. And from a plot perspective, that white character also helps fill out the christianization of Japan subplot.
It could very well be the same with AC. That they picked a black samurai outsider could be a relevant plot point. That it is this one in particular - who had close contact with Nobunaga - may also be central to the plot and story they want to tell.