You can say the same thing about sub content. Really I have no idea how Kiyoko fits into "aggressively subby" or "small shivery prey" even a little bit. Brienne is if you want a super slutty girl in the sheets but super loving girl in the streets, Azzy if you want something gentler and sweeter(heh), Valencia if you want a very shy but very willing partner, Cait if you want something super casual, Cat Harem if you want to feel like pampered royalty, etc. Kiyoko, Azy, Etheryn(high confidence), and Cait definitely don't fit into either category.
Sorry, I haven't really played fox content, so I can't actually speak to Kiyoko specifically.
But I'd personally categorize Brienne, Cait, Cat Harem and high confidence Ryn into what I'd call "aggressively subby", and Valencia and low confidence Ryn into the other category. Azzy I don't really think of as that much of a sub in the first place.
I'm not saying the characters have zero differences, but I think in sex scenes they show fewer differences than the doms.
I also thiiink (not positive though) there are more subby characters, so it just might also be the number coloring my perceptions.
Again, at the end of the day, they almost all make you feel like a piece of meat. Something that they use for pleasure and don't really care about what happens with you afterwards. There might be slightly different flavors of it, but they all have the same general attitude when it comes to the champ/sex. I actually feel different characters view me differently with sub content where they could view you as a spouse, a fuckbuddy, their owner, or just a way to blow off steam; while with dom content they're all just "I'm just going to use you for my own pleasure and you're going to (hopefully) like it."
That attitude isn't the only difference between them, though. Orlaith and Mara's sheer physicality isn't the same as Lyla domming your through degradation, or Hashat's single minded dedication (if you're an elf), or Arona's joy in actually constantly reminding and demonstrating your place in your relationship as well as her switch to a more caring side when your pregnancy happens, or Eryka's fits of violent dommi-ness...
Skill(writing) issue. For some reason these writers are afraid to give the champ personality in any scenes unless it fits their own narrative. It's not too hard to still let the player feel in control and self-insert while also giving the vessel they control a personality of their own. Wsan does a pretty decent job at it but when TOBS writes it for example, the PC may as well be one of those hentai protagonists with hair covering their eyes. Wait those guys actually have more personality than the way TOBS writes the champ...
Whatever the issue is, the result is that player dom scenes, imo, have noticeably looser and less descriptive writing. And I don't even think Wsan is immune to that; he barely writes player dom in the first place that I can remember. He generally writes his scenes to have a bigger focus on the NPC, which is why I think his sex scenes are so great; they're really good at showcasing the personality of the characters in them.
I think Tobs tends to actually focus a lot more of the player's thoughts than other people which...doesn't always have great results. One of the only times early on I did some fox stuff, I did Rindo's first sex scene, and noped out when he tried to intimately describe your character's reaction to her burnt bits during sex, and how you were banging the trauma out of her or something...it was pretty bad.