anecdote: in my elementary school there was 1 gifted teacher, where over the day, each grade's gifted kids (we had about 100 kids per grade, and 6-7 qualified as gifted in florida) would go into a class with the gifted teacher for an hour or so.
I also was far enough ahead in math that to help me stop being a disruption (I was not one to sit still) I was sent to help in the special needs class. IIRC, there were 6 kids in that class, and 2 full time teachers with special training.
I don't think it's crazy overfunding. I saw first hand that if you just get the few really gifted kids away from drudgery for an hour or so and challenge them with creative learning, In Florida the entrance was usually based on an IQ test given at a young age (I took it at 5). So oddly, across the students I remember, I was from a wealthy family, 6-8 from middle class families, and 2 from poorer backgrounds. it helps a lot. And frankly, the kids who are learning disabled I gained a huge respect for. My experience with the disabled is they usually try far harder than almost anyone else. I know if I had so much trouble wrapping my head around addition I would have given up way before some of these kids did, spending years trying to really "get" it.
But this is one state, and 1 district within the state. I've heard of a lot worse.