In my world building, I have an explicit Law-Chaos axis.
Road and Wall societies are on the Law end of the axis.
Hill and Sky societies are on the Chaos end of the axis.
As I want extensive wilderness, but also want huge cities, I make my worldbuilding cause this.
Road and Wall exploit high-density magical ley line intersections for their cities. They use this magic to generate extremely high yields for crops near said cities. This allows us to have very urbanized populations that aren't at the head of continent-wide peaceful farm food trade networks.
The Walls of this civilization are magically warded -- down to the walls of individual homesteads -- as are the roads. The roads travel along ley lines, with shrines along them, where travelers perform rituals that reinforce the wards. The roads are less protected than the settlements, naturally; but this allows nasty monsters in the wilderness, but still with a trade route that goes through it.
The Road and Wall civilizations rituals are about reinforcing these collective protections of their society. You pray for the wall and the road at major rituals, not yourself.
On the other end are the Hill and Sky people. They control most of the world in terms of land area, because their food production is not intensive like the Road and Wall people. There are more Hill and Sky people, but with a lower population density. Hill and Sky survive by making deals with the local spirits of the land, who shield them from (most) of the deadlier monsters. These relatationships are personal, individual to spirit, and their societies rituals support these one-on-one bargains with the spirits. You find your spirit guide to become protected by, you sacrifice part of your kill to the spirit protecting your prey, etc.
Lawful here means loyal to systems and rules. Someone who swears loyalty not to the Queen, but to the Crown, is making a Lawful oath.
Chaotic here means loyal to people and individuals. Someone who swears loyalty to the Queen, but not to the Crown, is making a Chaotic oath.
Now, two Chaotic societies will be no more likely to be allies than two Lawful societies will be. And many societies will bridge the gap between them, or even use a different way - a different axis - to deal with the dangerous world.
Using this model, the Orcs are Chaotic. They have managed to overrun a number of dwarven fortresses (ley line nexuses), probably by learning of a new way to deal with the dwarven wards (this might require great sacrifice however! Or maybe the attack technique just weakens them; the dwarves fell because they relied too much on the wards, the cities that hold know not to place too much faith in them).
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I like the Viking idea. Part of the pacts the Orcs make require you to prove your worth as a warrior to the spirit you are making a bargain with. So they go out a-Viking, engaging in raids and proving their worth in combat.
With their society being constantly surrounded and attacked by the Road and Wall civilizations, a taboo developed against proving your worth by merely fighting other Orcs. This change was part of the reason that let the Orcs overrun the Dwarven cities. Prior to this taboo, Orcs would slaughter each other in great numbers as part of these rituals, and if an Orc wanted to prove themselves a great warchief they would engage in a massive civil war.
With the taboo, the raids are on the Road and Wall people's (weakening them as much as the raids weaken the Orcs), and a Great Warchief leads the horde not in a civil war, but against the Road and Wall people.
A true horde requires about 1/5 of the Orcs warriors to gather; back in the day, another 1/5 would rise up against it. Today, the dual Hordes still form, but instead of turning on each other, they head out in two different directions; whomever produces the most glory wins the competition.
At 40% of the Orcs' warriors, a massive loss is painful, but wouldn't leave them open to being counter-attacked. I mean, you might take back the outermost settlements, but most of the Orcs' warriors are still ready to fight.
And defensive war doesn't require a warchief.
At the same time, Orcs have no need to actually wipe out their foes. A foe completely destroyed is no longer a good foe to fight. With the taboo, you want to keep your opponents strong enough to be a challenge; or you need to find a stronger foe once you dispatch them.
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I had a different model for goblins in one world I invented. Here, Goblins embody "you are what you eat". Goblins are born as larva, and the adult Goblin that is born depends on what the larva is fed.
Goblins will mostly breed true if fed Goblin-meat. If you feed larva wolf, the Goblin is born as a dire wolf. If you feed them a bear, you get a bug bear. Etc.
Goblinoids believe in reincarnation, and they have proof. The larva can remember some of the knowledge that their food host had.
What kind of Goblin you get out of a larva is not fully deterministic, but Goblin societies learn how to guide it. So Hobgoblins learn what mix of what meat produces Hobgoblins (often mostly Hobgoblin!), but all Goblin societies feed for specialty workers.
Having your meat return to the larva is important; that is how a Goblin lives on past their score-and-four years. Long goblin lineages can go back centuries, producing goblins who remember the distant past. Worthy foes will have their meat incorporated mostly intact into goblin larva to bring their strength into the tribe. Unworthy foes will have their meat ground up and scattered.
