Ok, theres bashful, sneaky, grumpy and Little Miss Shy over there at the back.
Orcs are dull-witted cave-dwelling scum found only in the magical realm of Middle-Earth. The Orcs work for Sauron - no-one knows why, they only know that they are willing to die in huge masses to achieve nothing in particular. Orcs are a unique race in that their defence systems are not great. The tiniest poke will kill an orc. Thats right, so an arrow in the finger will immediately kill and orc, and then even something as stupid as a whack on the head with some staff will kill an orc. They really are very weak, weaker than Grunts, weaker than Sentinels, and even weaker that the hapless Stormtroopers.
The Orcs are one of the races that rebel against the League, so the League declared war on them. The League has no power over the magical realm of Middle-Earth, and getting there isn't easy, so no battles have taken place in this war yet. The League instead relied on the 'Goodies' in Middle Earth, who eventually brought the Orcs to a ceasefire and they have now been intergrated into the League.