Definitions from Webster
A) "Contrary to" means "in conflict with". Properly infers that the ancient victors did X in conflict with popular beliefs
B) "In contrast with" is a comparison of similar objects to set off their dissimilar qualities. There is no comparison here.
C) "Opposite of" means contrary to one another or to a thing specified. Once again, there is no other thing for "popular belief" to be compared to. Well, at least, comparing it to Greek victors would be wrong.
D) "unlike" means marked by lack of resemblance. This changes the sentence meaning to ancient victors did not resemble popular beliefs?!
E) "In spite of" means "in defiance of". Again, this means that victors defied popular beliefs?