Sounds like a good way to organise. I generally go with creator, genre and franchise but clearly I like to make things difficult for myself because that can get messy.
For example do I put the whole Patlabor franchise with Mecha shows/movies or with Mamoru Oshii's other standalone films/TV?
In terms of genre they're arguably comedy as well as Mecha which also complicates matters.
It would definitely be weird to separate his Ghost in the shell films and put them with other one off Oshii works since it's part of a larger franchise. I mean the other entries sometimes involved him in some way but he didn't direct them all so those are easy enough.
However......what about the Kerberos series? After all he directed both of the live action films The Red Spectacles and Stray Dog that both take place in the same universe as Jin-Roh, which he also directed. Do those 3 films go on the shelf together? they're all part of the same series and directed by the same guy but two are live action and one is animated. Should i stick these two alongside my other Japanese movies? Oshii directed other films that were stand-alone, do I just put his live action films that aren't connected to any anime together and keep his ones that are mixed media but linked together on the same shelf?
What about anime based on American properties which i also own movies of? Does Batman: Ninja go with Batman movies or anime? or alongside Batman: The animated series?
These are just two examples of the conflict in my brain
