Victor_Weismann
The only way I see a Harem for Anna is if they were "traps" that respected Leon as the alpha husband. That way Anna could satisfy both her and Leon in bed. Anna is too Yandere to allow herself to get a wife that is a woman. But a beautiful man that is a trap would satisfy his cravings for a Harem probably in her opinion. Of course they would have to be worthy of the Alucard family as well. She could be influenced by Victor's wives and Victor himself that a Harem has many benefits for the family. Especially since Victor could turn them into his sired race. Also with her being a very Yandere wife she wouldn't want Leon to feel insecure about his looks which is why she would only get traps that are beautiful and strong. Especially ones that have their true selves as traps and help her with having more attractive children along with Leons children. These traps could be labeled as Wives instead of husbands as well so Leon is respected as her husband in Vampire society. Anna could become someone like the Adrastia clan with her strength and beauty.