While I'm not discounting your points, I have heard/thought of some other arguments that make the case for Parvati's win.It’s an impressive win for Parvati, but in no way can this win be an equal to Tony’s (and Sandra’s) two wins. A 16 day season, Parv and Cirie having an automatic ride or die, and unequal starting tribes (4 women to 3 men). Again, a very impressive win, but not equal to an American season of Survivor.
To the point of Parv having Cirie there with her, Tony had Sarah as a ride or die on his starting tribe in WaW. Yes, they became enemies in Cagayan, but they clearly had a strong bond outside the game that wasn't going to break.
To the point of the women having the advantage, that is true. However, you could also look at it through the lens of the International players having the numbers advantage over the Americans that Parvati overcame.
I also heard the argument that Survivor should be focused on "votes survived" rather than "days played". Parvati this season actually survived more votes than Michele in her winning season. Tom and Erika went to the same number as Parv. Yul, Bob, Earl, Maryanne, Natalie, Amber, and Brian only attended one more Tribal Council than Parvati. Parvati in Micronesia only attended one more Tribal council than in AU v World. When you look strictly at percentages (which may not be a great argument if you're making this case, but I'll share anyway), the only winners of US Survivor who attended a larger percent of Tribal Councils than her were JT, Vecepia, Nick, Natalie, and Denise.
Then, of course, you look at the level of competition. While a smaller cast, they clearly were better competition than many of the US winner had to face. And compared to the early seasons that had 16 players, this cast only had two less, which isn't that drastic of a difference.
Again, I'm not discounting your points, I just heard more arguments while listening to podcasts. I'm still not sure how I factor this season into overall rankings. I think my biggest thing is, if I take this game into account, I should be looking at all Australian Survivor players. It blurs the lines between the two franchises. If I do factor this in, I think Parvati is the best of all time, even if we don't weigh this season as heavily as others. If we don't factor it in, I think there's a conversation between Parvati and Tony (and some would throw Sandra in, too).