For lack of a better name, as 'A Mad God Rising' was really intended to be the pseudo title of a specific campaign, and I have yet to name the world, or the lands, so I have decided that Shardheim will sort of be the name for the setting. Even if various groups, because this setting is sort of where I have placed the Emerald Spire for my Pathfinder group, and is sort of where my ACKS campaign is also, never directly deal with Shardheim itself, I like the idea that it is enough of a thing that in the world people know of it, even if it's mythologized, or exaggerated.
On to the orcs.
The orcs are like the moogles. Both are from someplace else in outer space. The difference is that moogles were long long long ago space refugees; their ancestors sort of planned to crash somewhere. The orcs are the descendants of purpose built soldiers. They were weaponized humans, or near enough to humans as this world is concerned. However, the vessel(s) that crash landed did not have a large enough gene pool, crashed in fairly isolated areas, sometimes deep fucking underground. Combine that with the weird engine radiation and you get orcs. Take a group of organisms engineered very specifically, with a largely homogeneous genetic makeup, never intended to breed in large numbers, or without supervision, with recessive genes that were never culled from the genome, and are large amount of mutagenic chemicals and radiation. Orcs weren't always the ravaging marauders of limited intellect. Even if their ancestors were essentially living weapons, they weren't stupid. Orcs today are to a large extend stupid, evil, and horribly inbred creatures. Well most of them.
Half-orcs are proof of how much variation between two human populations there can be and still result in fertile offspring, or orc dna is really really robust. Half-orcs greatly tend to favor their human side, baring the tusks, green-grayish skin, and almost supernatural resistance to being knocked the fuck out.
Some times there are ancient ruins where the walls are made of seamless metal or some soft waxy substance, and on the walls and doors are a language undecipherable without magic. If someone were to spend years comparing the characters to how orcish sounds, it would become clear that the language of the orcs is descended from the language that was spoken with these symbols.
In some of these ruins are deadly traps that slay all who enter except for orcs and half-orcs.
Some orc tribes still hold fast in these ruins, and may even have a few (mal)functioning weapons of ancient power that only those with the proper orc bloodlines can operate (the least amount of genetic variation from the original orcs, or at least the correct specific genes).
Despite both being green, orcs and goblins are not similar species. Goblins are faerie creatures, and won't poison you if you eat one. You might have a bad trip if you eat a goblin, but you probably won't die. Orc is for some reason or the other poisonous. Heavy metals, radiation, hyper-active immune system, nanites, pick one and that is probably how eating orc-flesh killed you.
While not related to pigs, despite the tusks, a great deal of orc tribes keep all manner of porcine beasts.
Orcs like large bladed axes, and hammers, and maces, and clubs, and spears, and rocks, and chainsaws.
Some orcs wear armor. Most just bolt it to their skin, or scarify their hides to toughen them.
Orc tribes that still mainly live underground hate light brighter than a quarter moon's and fight as if blinded. Sadly, most orc tribes live above ground and can probably see and smell better than most adventurers.