I understand what you're saying and I sort of agree. I was going to suggest that Hunter only wins somehow when he gets to the pussy
before Sterling, but in chapter 9's "blind/deaf" bad end, Hunter has his way with several girls
after Sterling has had sex with them, including Eva, Mallory and Catherine. It makes me think he'll never stop being a threat; even after Sterling wins the race (so to speak), Hunter is just waiting for his chance to steal the trophy. Hunter will have to be stopped permanently before Sterling can let his guard down.
While the aforementioned scene was a fast montage, it might be interesting (psychologically) to have a more
detailed bad end featuring one of Sterling's lovers
after they've been together. I'm thinking something dark like the Femto x Casca scene from Berserk, but most players probably wouldn't want to see something like that.
As for the penis size debate, listen to Eva, she's something of an expert on the topic: