>In my opinion, best faeries would be humans but with all the defining characteristics of an arthropod or insect.
Rather than a fairy, you want tiny bug girls. They're different.
The wings alone don't make them bug girls, like how pointed ears don't mean they're elves. There are other factors you use to specify what type of monster girl they are.
Just look at Cirno. Her wings are icicles, which are different from the usual bug type. Despite that, she's still a fairy.