This is not my area, but I will respond with what I think.
I think people don't think about it that much, however the connection between Pharisees and Persians isn't quite that strong. The Jews were regularly overrun by other governments (Judges, Chronicles, Kings, Samuel). The Persians were just one more feather in their cap, and the Jews made it their business to benefit whomever they were captive to. The Persians were nothing like this. If they were captured, they disappeared. They didn't believe the same things as the Jews.
The Persians were not like Pharisees in many ways. The Persians were the upper crust. Pharisees were besieged by anti-cultural governments. Persians didn't 'Hold the line' or see a reason to establish their way of life beyond the immediate and practical. Their Astrology was for hire. Their concept of 'Immortality' is probably what caused them to drift and let go of their culture, and their 'Faith' disappeared in time. The Pharisees, on the other hand, believed they had a duty to preserve what they had been entrusted with. They may have argued for immortality, but they also listened to reverse arguments. Is that characteristic of Persian faiths? Its also likely, IMHO, that their idea of immortality was not at all the same as the Persian one. Pharisees were about Law, about finding wisdom at a young age and about passing it on to the next generation. They felt everything depended upon their descendants and not upon ghostly 'afterlives'.