The "enslave centaurs as mounts" thing might seem logical to a layman but to someone who's actually read up on how cavalry actually works (and doesn't) it's a load of horrendously impractical nonsense. Shortlist:
* they're actually on the small side by horse standards (meaning relatively low carrying capacity) and as sentient beings with long maturation cycles fundamentally unreceptive to the kind of selective breeding that IRL slowly pushed up domesticated horse sizes over, oh, three-four millenia or so
* the upright humanoid torso in front is going to get in the way of any meaningful weapon use by a rider a lot; it's also terribly vulnerable to enemy weapons, much more so than the neck and head of a horse are, and will need to be protected somehow 'less you fancy your mount keeling over about instantly - in practice meaning armour which both drives up operating costs and eats into the payload capacity
* to be effective in combat unquestioning trust and authority must exist between the rider and the mount (and even so IRL the more common causes of death and injury among riders stem from misbehaving mounts already outside combat) which is incidentally why cavalry horses have always been much more expensive and valuable than basic riding mounts and beasts of burden - not only are the physical requirements higher but they need a lot more training; trying to ride into a battle a sentient creature that almost certainly hates your guts and is entirely capable of actively plotting your demise is basically suicide. Same issues kind of kill the rider-mount coordination needed to effectively employ weapons on horseback. And hoo boy are you going to be but fucked going up against free centaurs - not only are the latter vastly more effective combatants but there's an only too obvious incentive for your own recalcitrant mounts to flip...
* near as I can remember the centaurs, unlike real horses, are not gramnivores (grazing grass-eaters) - presumably they eat essentially the same stuff as the other sapients of the world (duly scaled up for their larger mass) which in practice means the logistics of feeding any larger number of the buggers are going to be quite the headache, doubly so if they're expected to be capable of strenuous physical labour. Incidentally should also make the bellies of their lower part slimmer than those of horses of analogous size due to the absence of the complex digestive systems needed to process cellulose...
All of which adds to the whole thing being a terribly impractical idea and blatantly inferior in every possible way to the buggers simply fighting themselves as, effectively, super-mobile infantry. In practice given the obvious advantages the centaurs have over the others in terms of mobility and sheer physical power they're far more likely to have formed (important part of) the warrior aristocracy basically everywhere they can survive ecologically, and there aren't very many corners of the world where I can think that wouldn't be the case outside the polar regions... Might've been combined with slave-soldier arrangements in places; the two are by no means mutually exclusive.
Note that they might well also have employed the historically fairly common cavalry practice of transporting light infantrymen who dismount to fight as close support; this has been used for both short-term battlefield purposes and longer-ranged "operational" forays, and parallel "escort" traditions existed with both war chariots and elephants (though the latter obv couldn't practically carry their close-support infantry).
This concludes today's installment of Applying History To Fiction With random-sensei; take notes kids, this'll be in the test.
last edited at Nov 8, 2018 7:03AM