In 50 years, the Amazon river/basin could have been geographically swallowed by a new political entity and renamed. Sure, that's much less likely than Amazon the company being defunct (I hope, that seems more likely to be harbinger of world disrupting changes), but I think it's also more likely than Greek mythological scholors deciding to change millennia old characters and concepts.
I'm sure we can choose a specific metric to make the Amazon geographic area win, just as we can for any of the others in this comparison, but picking the metric to match the outcome we want doesn't seem the right way to go either.
I can definitely see cases for all of them, and I don't know the right metric by which to judge. That does make this an interesting case IMO, as the likelihood of the losers to be upset is high (except maybe Greek mythology, since I don't think they have a strong lobby on their side).