@Mindaledoe
OOC: Well humans came to Equestria as space visitors(Equestria is its own planet in this) and are advanced as you’d expect space travelers to be. Some of them were from Remnant(the planet in the RWBY show) and the grimm monsters from that same show appeared on Equestria(you should look up the RWBY wiki about those thing there’s description but also pictures and the like).
The most powerful human faction on equestria right now would be the NOD, a faction from command and conquer played by Cerebrate. It’s been a while since they last acted but they are there in the background to be referred to. They control Japony though a local japony government aligned with them.
In the diamond dogs recent past, There was the electric revolution started by a pony scientist who took refuge in the tunnel and ultimately integrated their nation. Now they have access to geomagnetic electricity harnessed by their unique underground position and their cities, at least their developed one, have all the light they could dream of and even underground agriculture is possible under artifical lights. It also began another great change though as magnetic guns became a thing and are the standard of diamond dog guard arsenal now.
there was also the short lived diamond dog civil war between the city of Corund and the rest of the tunnel civilization. Corund was heavily militarized and followed a philosophy that civilization in their final stage are all warrior culture, but despite of this they were defeated because of the great combat potential of human who sided against them as well as changeling and it was just too much.
There’s more but it’s the kind of thing to say as it happen and become relevant.