It's a common saying that an akita can't easily co-exist with other dogs of the same sex. Indeed, setting the limits and calming the akita in order to avoid tension at home isn't very easy for many akitas.
My experience is limited to a female akita living with other 2 female Shih-Tzus and a female cat.At least for the cat I have to admit that I didn't do anything special, this cat decided it was safe to come and demand to be adopted by a family with two Akitas roaming in the garden. A cold winter night she fell asleep on our balcony. I guess she had her way to show the akitas she wasn't prey and she slowly managed to become part of the family. When the third akita of my life came home the cat was already here and they somehow figured out how to live together in harmony.