For what it's worth, I think trying to precisely define the WP on zoogeographical terms is a rather pointless endeavour.
Who actually cares about / uses these boundaries in a practical sense? Is there anybody apart from geographical listers, and authors of regional texts, both of whom need an agreed definitive cut-off point rather than endless ruminations about Chadian enclaves and Urals.
To me, it makes sense to use political boundaries and, with the obvious exception of Russia and possibly Kazakhstan, either include or exclude entire nations. So, for example, include all of the Arabian Peninsular states, all of Iran, all of Algeria, but boot out all of Mauretania (sorry, Grey Woodpecker), and all of Chad.
When it comes to Russia, just do the same - decide where you think the boundary ought roughly to lie, and then have at it with the political boundaries of the oblasts, krais, and autonomous okrugs!