Okay, but I'm pretty sure that Grumpkins & Oakly the Treeman have no sexual interaction with the MC
Also, it depends on how much Tinekere is inspired by this or that folklore for each character. In Eastern European folklore, fairies are gentle, kind creatures. In Celtic folklore, they're bitches.
I don't disagree with your opinion, but for me it just doesn't quite fit here. Or rather, it's taken in a different direction.
Maybe theme for sequel
I'm sorry but I'm gonna be that guy. Celtic Myth is a sub-form of European Myth... all throughout Europe in the age of myths & legends Fae have always been fickle creatures. Greek, Celtic, Slavic, Germanic all these cultures have Fae as nature spirits & deities that are fickle, unpredictable & at times complete bastards. The Wild Hunt is found ACROSS all European cultures (with different names) & are considered Fae, but they behave like demonic huntsmen. The Unseelie Court (which is predominantly Celtic) is a faction of sadistic & cruel Fae, while the Seelie Court are never "good" their just less likley to play you alive or kidnap you're kids. They can still do that if they desire, their just less likely.
When most pagan cultures were absorbed into the catholic faith the Fae were twisted into, at best, the fallen children of Adam & Eve, & at worse nature demons.
The modern western concept of Fae being spindly, good natured & whimsical is a relatively recent development in the last 100 or less years where fairytales stopped being extreme cautionary tales & became all "Happily Ever Afters". We have seen that Grumpkins are wrinkled short folk who apparently need other females to breed with & Treemen are hulking nature spirits so I can imagine Fae being more varied in their nature. So they could be made to fit the feel of this world, perhaps a Celtic-style Warrior Queen for the Seelies & a gothic-style femdom for the Unseelies for example?
Heck Elves & Dwarves are Fae, it's just modern media (usually inspired by Tolkien) that makes them part of the mortal races instead of denizens of the Faerielands. The concept is as broad as Demons & (biblically accurate) Angels.
So I guess I was wrong. Which whores eat children? Or which ones fuck men to death? There are so many different folklores that one gets lost in them...
The Fae can be very kind & giving but they run on an unknowable morality. While we have Black & White, evil acts are evil, they have Blue & Orange, you do good by I'll invite you to my wedding. Oops how I didnt realise u just missed 27 years of you're life partying with us... sorry my dude. There are plenty of stories where Fae just dont realise how mortal time & biology works so even when they are nice they can still inadventatly hurt us...
But that's nothing compared to when evil or vengeful Fae WANT TO HURT YOU. Those stories get dark & can be found throughout the before mentioned cultures above.