I never saw Marius as androgynous (I see Antoine, maybe Nikki, Gabrielle, and Pandora as androgynous–with the latter only doing so if she feels like wearing masculine clothes); I always saw Marius as the most masculine looking out of the vampire. Lestat would have something very feminine about the way that he carried himself, Louis would be too beautiful to be considered masculine, but Marius was an extensive traveler in ancient times as mortal, he had to be strong, and tough.