in my campaign i made goblins into a sort of nazis: very xenophobic, but also very nationalistic, willing and eager to lay down their lives for the goblin nation against their enemies (which amounts to everyone else). this kind of society can actually exhist and be a pretty dangerous foe.
orcs don't have a real society. their only organization is a bit of religious respect for their clerics, but aside from that, the only right is that of strength. the only thing that keeps them from killing themselves is that they consider women as cattle, so they are spared from all the violence. even if 90% of male orcs die before reaching maturity, those who survive can start an harem and perpetuate the species. but orcs aren't really dangerous as a whole, and any seriously organized military can easily wipe them.