Which is, indeed, a very good point. But it's a characters with a lot of space for character evolution. Mason already said that they enjoyed getting intimate with MC, and cuddling after. Provided you picked 'Mr Nice' path. They could decide they like men too, afterall, and them and MC can build a relationship where they retain their male identity and still them and MC menage to find their way together.
As long as they don't go through a gender reassignment surgery. Or at least if it's VERY optional and VERY avoidable. (Please, please, please, NEON GHOST, don't play an Elliot Page on us!)
While Ashe is quite a bidimensional character. She's just any blonde hottie with limited brain capacity who doesn't seem to want to be anything else then a blonde hottie with limited brain capacity, but drilled a lot through the gameplay.
She gets more interesting if one plays the dark path and her story might become saving herself from a (heavely) abusing relationship or digging deeper and deeper into it.