The nazis modeled a lot of their Reich on the Roman state (the eagle iconography was used by both). The Roman salute was just something else they took from their idea of the Roman empire
So I’m with you, I have no idea how “it’s a roman salute” is supposed to make anything better
My input: I’ve never searched for papers in Scihub directly. I usually find them off Google scholar or something, and then put the paywalled URL or the DOI (an identifier you can usually find in the paywalled website) in Scihub to go to that paper. I don’t think search capabilities are in scihub’s scope.