I 100% agree. I prefer 4, 5 good LI on whom I can focus. Side characters are welcome too, but not as main LI.
As for the part I highlighted, honestly I wouldn't call that a fetish. Don't think of yourself as weird.
To me, fetishes are something more peculiar: an object (shoes, piercings, etc.), a setting (public sex, etc.), a taboo (incest, teacher/student), or a part of the body that is not per se related to sexual appeal (feet, hair) which one prefers or needs for sexual arousal.
It's normal for a straight male to be attracted to a juicy female ass like Sarah's. It's a sign of fertility and femininity