Of all the races in the Greater-equestrian solar system there are few that are quite as technologically adept as the native species living on Gamma, a planet orbiting around Celestia's sun unlike the rest of the system's heavenly bodies. Proto-Centaurs are very pony-like from the waist down but that is where the similarities end. Proto-Centaurs tower over most equestrian species — to such a point that even the females can stand eye-to-eye with the largest of the princesses. Proto-centaurs do not have any dexterity in their pony-like limbs which seldom leave the ground, but mostly use their minotaur-like arms to grasp, manipulate, gesture and fight with.
It's largely tanks to the planetary structure of Gamma that gave the Proto-Centaurs their tecnological advantage. While they have no magic of their own, magic is still extraordinarily abundant in the form of Uranium Arcanite, a radioactive, magically dense metal known better by the Zebra name of "balefire". With this, they have crafted powered armor, energy weapons, advanced vehicles and other useful technologies to compensate for what their natural capabilities severely lack.
Proto-Centaurs do not have a monarchy like the kingdom of Equestria, instead following a philosophy of meritocracy with the intent that its individuals constantly better themselves for the benefit of others— and therefore themselves in return. This is a philosophy that comes into conflict with ponies who cease practicing skills at an educational level once they find their special talents. (After all, why learn how to do anything else when your special talent fits you perfectly into society?) Despite this, Proto-Centaurs had found a particular fondness for ponies during their first contact, finding them cute and charming. This trait helped the ponies during their initial meetings but continues to hinder proper political discussion to the present day.
Proto Centaurs have a policy to initiate first-contact with extra-planetary species only when they master interplanetary travel, and had been passively observing the other races before then. However once they discovered the ponies' capability of "skythreading", a primitive method of travel to other planets by walking a thread linked from one point to another across space, they beat them to the punch.
Supplemental thing for Redblak— a tumblr blog I've basically discontinued, but still like writing in passing sometimes.