Hello, I'm not to invested into Legend of the 5 Rings, but I do have a few of the RPG rule books and I enjoyed it. The last one I read was the Great Clans book and I noticed something. In the discussion of the Great Clan families I saw that the Kitsu and the Kitsune have a similar history. Both were small groups persecuted by the Lion Clan. They have similar names. Both are family of Shugenja who, iirc, have some specialization in the spirit realms. Different focuses on who they deal with yes, but there is a parallel.
Their histories are different. But, I like to take the view that the early history of the Empire is vastly distorted (I came up with my own history, but you wouldn't care for that). What I think is possible is that the Kitsu and the Kitsune were both surviving groups of a bloody slaughter at the hands of the Lion. They ended up surviving, but it was not guaranteed. Possibly not only the early Kitsu were driven out, but the entirety of the Unicorn clan may have been driven from Rokugan.
I recognize that this contradicts the lore, but it is an idea which I found interesting. And from a certain point of view I think this is quite possible.