I personally think it boils down to your ability to use what has been given to you. The Sassanids were fire worshippers, while we Turks worshipped the eternal blue Sky. Our conversion merely gave us a point of legitimacy in our new areas of Conquest, while your conversion made you even more dormant and inactive than ever before.
Üze Tengri basmasar, asra Yir telinmeser, Türük bodun ilingin törüngin kim artatı udaçı erti?