To answer your question, first some history. Iran has always had a tradition of Freestyle wrestling, Greco Roman wrestling is actually called "foreign wrestling" in Persian. I remember when Iran got it's first gold in Greco Roman by a street vendor in the late 1960's, early 1970s when I lived here, how shocked everyone was.
Fast forward to 1983 when another Iranian named Mohammad Bana won a silver in the world championship, and a gold in the Asian championship.
He later became the coach of the Iran team, and did a great job of building team. That increased interest in GR wrestling, the traditional regions that were strong in FS wrestling, did not show much interest in wrestling, but regions that historically did not participate in wrestling became very interested in wrestling. Places in the south such as Khuzestan and Fars now represent most of the GR wrestling talent from Iran,
Thanks for the info about Khalili's Russian opponent. I guess we will soon find out.
Youssefi vs Haines should be a good one