Hive Mind
It's interesting to see all the different interpretations of Goblinoids - perhaps a sign that the Monster Manual description offers just enough background to fire up people's imaginations without forcing them into a narrow conception. For my campaign Goblinoids were a hive mind species originating in an alternate material plane (where they had wiped out all species other than their food plants) and brought to the Prime Material Plane as a weapon in a devastating magical war several centuries earlier.
The hive overall was Lawful Evil and highly intelligent, Goblins are workers, nearly mindless food gatherers. Hobgoblins are drones, with independent minds (though less than human intelligence), who roam in bands at the perimeter of the hive's territory in search of treasure to bring back to the queen in order to prove their worthiness to fertilize the queen. (The queen was modeled after a greater Slaadi, mating was almost always lethal.) Bugbears were inner servitors, with both independent intelligence and access to the hive mind. Bugbears and hobgoblins had the ability to pick up character levels if they survived long enough in the right environment. The hive also had the ability to generate large monsters, mainly an excuse to use creatures that I thought were interesting, but couldn't figure out how they would fit with the rest of the world, like Athaches.
In one campaign the characters spearheaded a military attack to wipe out a Goblin hive, in the next campaign they negotiated a treaty with a hive, trading metal working technology in return for food and raw materials.
Orcs are (usually) honorable warriors and related to humans, sort of a cross between Klingons and the Golden Horde.