So a caution on making a Zoroastrian Kingdom; if you started Catholic it doesn't look like you can change investiture laws once you go Zoro...you can yank Bishopric titles and hand them off to loyal Zoroastrians in your court (in which case they become Baronies{?} but you still get church taxes from them). I'm testing again by changing investiture before my Zoro heir takes over; and I'm hoping that will let me introduce my own claimants so that the Pope doesn't keep putting Catholics in place.
You can declare holy wars against other realms (I assume they also can declare holy wars against YOU, but nobody did to me). I'll put in another update later after my tests are done tonight.
How did you get that to happen? Are there any characters (landed or just courtiers, w/e) anywhere that start off as Zoroastrian?
Except that it obviously would? First of all the thing to "Fix" in your situation is the survivability of Pagans, not "they're wiped out on Day 2 so who gives a shit!"
I realise that the real reason that all pagans are grouped up is so that they can use religious defence to help each other... What you don't realise is that this is not effective because: a.The only real Pagan 'player' in CK2 is the Cuman Khanate and, guess what, they don't give a crap about those pesky Lithuanians. And why should they, anyway? The real problem here is the way that the HW CB works atm. So, yeah, I couldn't possible care less about what this will do to the survivability of the independent pagan realms because it shouldn't have anything to do with it. You said it yourself, these religions have nothing to do with each other, other than that they're not monotheistic and therefore should feel no loyalty to each other in times of war.
I don't want to see the Cumans rush to Lithuania to fight the HRE because, somehow, they feel that the Lithuanians are their brothers in faith; that's retarded. I DO give a shit about the pagans, but this is not the way to protect them. Instead, we should find a ssolution to the actual cause of the problem, the Holy War CB. I won't settle for anything less, like pitching all the pagans in the world against the Christians, which is not even working anyways, or is it now? If it did work, then I would at least feel that there's a reason for this ahistorical grouping. But I digress. This is a thread about the current in-game representation of Zoroastrianism, let's not derail it.