I would say Hawkgirl and Vixen are better enjoyed together. That could be really fun in some form of event.
I havent done Hawkgirl's cell route yet. But people said.. wait I think you told me that she is by far the only heroine who doesnt enjoy the acts with Luthor no matter what.
So it would be weird if she gets a group sex with Vixen. Because Vixen feels the opposite about the matter with Luthor.
Persuading Hawkgirl using Vixen wont work, but she could if she tricks her to it.
Hawkgirl doesnt seem like a tsundere like most heroines, her resolve seems firm.
Its like she only wants and prefers BBC (John Stewart).
Makes me hate her even more in that regard.