These voices captured based on current voice structure of the game and i was asked to follow the existing structure , and I agree with you some of them may not be a good choice.
Although there was a design that I suggested to implement for voice structure , and it was for whole game not only Persian but it require development and we didn't have volunteer to implement it and sadly i cannot help on development part.
you can check this post:
if we can find someone to help the development part , i promise you in next release the Persian voice to be perfect