This is no easy feat in EB. You would need to change the government system, seeing as Saka is nomadic, change the culture type, change the EDB extensively (which in vanilla might not be that hard, but try changing EB's by hand and it is virtually impossible), and lots of other things which I can't think of at the moment because I really should be asleep. Basically though, you adding a completely new faction, how are the Saka Indian in any way. I know they have the reforms, but they are still the Saka using Indian units, they don't changed culture and what not.

PS. Everything I've written is probably wrong because like I said, I really should be in bed. *looks for sleeping smiley*