Is it just me, or is the Warg Rider situation a bit of a mess for us that play Isengard.

They aren't better than the Warg Riders in Mordor, just a wee bit better (throwing weapons) than Wargs in Moria, and can only take 6 companies instead of 9. Why are they rare for us, but common for them?

I think I'm going to play with them as allies from Mordor when trying to field legendary companies to not only use one rare slot less, but also gain another common formation to let me keep my trolls and berserkers.

I'm not too happy with GW on that note.

Looking at the cost for the Orc Captain and then comparing it to Thrydan Wolfsbane also makes me wonder. Why shouldn't I just choose this epic hero instead of the Orc Captain? (apart from his "fluff" special rule Wargbane that makes it a bit odd to see him travelling with them)
He has the same fight and might, but 1 more courage and resiliance! Not to mention Epic Strike!
(and the benefit of being able to move around like an Epic Hero if needed elsewhere, along with his special rule against Rohan)

So, other than having filled up your quarter of allies, who's not using Mordor Warg Riders + Thrydan instead of Isengard Warg Riders + Captain?
Or have I missed something, and do I mount him (or Lurtz/Saruman) on a Warg or Horse?

Its all about the fluff i guess.

GW wants you to use special characters, perhaps because they make the battles more epic and enthralling ?

Or perhaps they just want to sell alot of metal models ?