Actually I think it makes sense if all Faunus' instincts are stronger than a humans. I mean it's what makes a lot of them a lot better a fighting and certain jobs so it makes sense it affects their dating and s*x choices.
A question that poped in my mind.
Why not tell Salem to summon 1 millions of grimes then he killed?
If she can't summon 1 millions just the max she could would help him no?