Centaur beyond the myth.
One of the general observations, when I write about centaurs, is that many readers only know the general mythology, hopefully, read about them or what they have seen in films.
It is difficult to quantify simply because every writer will have their own ideas, this includes the physical aspects. As an author, I find it more convenient to say that our centaur is a combination of two halves. That is the human heart and lungs. With a certain amount of cross-blood circulation. You get twin breaths, one long, one short. This is because just having human lungs could not oxygenate the blood enough for the horse's body as well. Retaining the horse's lungs makes sense. Food is a subject dear to many centaurs, one which I will cover later.
Take our little group here. We have a male centaur, which could be a stallion or if your dimension is cruel a gelding. Don't look at me like that, males feel free to wince and cross your legs. Next in line is a thoroughbred, or a human-equine shapeshifter.
Centaur foals, like the fully equine equivalent, grow up quickly. Mainly because they originally came from a prey species, or at least their equine part did.
Other differences can be genetic, human, or horse ears.
My centaur characters can use telepathy for private conversation, many equines in my stories are sentient and have this same ability. In this dimension, Epona the Goddess of horse and hound stopped equines and canines on earth from talking to humans by using a mind block.
Centaurs can also be based on a draft frame.
here we have from left to right, a Clydesdale Stallion, a Thoroughbred horse, and a centaur based on a draft body, alongside a four-by-four car to give a sense of scale.
They say you know you are on the right track when your characters talk back to you, and before you ask yes, I am taking my medication. It's not so much an out-and-out rebellion more that the characters develop into a fully formed entity. I supply their whole being, motivation, successes, failures, family, love life, and even a background history, no wonder they want a say in the matter.
Some young centaurides have enough of a sassy attitude to warrant their own part in a story. Tansy of the Bride Port herd is one such character, although she must toe, or is that hoof the line? An Amazon Kindle moderator did warn me that Tansy had to be seen to wear a top so as not to offend our human sensibilities, although nudity is no big problem within centaur society.