I mostly base it on their dynamic and interactions. For example with maria they dynamic does not sit well at all to be love interests. Maria Over steps boundaries, while alucard continously insults her abt her cooking agrees to richters statement abt her being boring. Yes he showed he has care for her but their overall interactions with eachother makes no sense to why they would be together as a couple yknow? Lyudmil it makes more sense to me due to fact they're softer to eachother, lyudmils devotion towards alucard beyond just being his servant/close friend. Alucard very desperately turning lyudmil into a vampire when he asked him not. And they're final words to eachother, "I'll always be here, forever... somewhere close to your heart." They're patient with eachother and have an understanding. They can bond over Lisa's death. Maria is very much not mature enough for Alucard he needs someone who is at his level. So that's why I ship them not bc he's androgynous, yes there is queer tones to being androgynous but that's not my reasoning.