Well mate sorry to be the bringer of bad news but the game reflects and bears symbolisms of IRL. Religion and political structures are the most obvious themes. I merely mentioned anything political from my personal view, just read again and you will understand.
More on topic,
Vanilla Horde: Recently recovered by the war and settled in Kalimdor. War did not end with peace but with Horde, actually orc, withdrawal from eastern kingdoms after the events that changed the leadership,
freed orcs from burning legion influence and closed the way back home.
-Garrosh status-> The whole situation never touched him. He was never corrupted by the curse of blood and was leaving in a paradise. Depressed, however, since the news of the orc situation were known to him but not to the full extend. He was aware of the corruption but not how it ended, hence his shame about his father's fel deeds.
TBC Horde: Portal opens back to outlands and kalimdor orcs travel back. They find a shattered planet as well as an untainted frontier with never corrupted orcs. Moreover the portal created another war front with alliance. The horde works against the plans of Illidan and Kil'jaeden eventually and the vastly majority stays in azeroth. Again peace was never made.
-Garrosh status-> Thrall informs him about his glorious past and takes him with him. Garrosh learns about the full history of the orcs, regains his respect about his father, redeems his guilts, finds self confidence and trains in new horde customs and ways in azeroth.
Wotlk Horde: Lich king attacks orgrimmar and Horde goes to war in northrend. Lich king is defeated. Again peace was never made.
-Garrosh status-> Challenges Thrall for leadership in a nevended duel. Leads successfully the forces of the Horde in northrend campaign, always trying to push things with alliance. Returns a hero.
Cataclysm Horde: Azeroth is reshaped and natural resources are depleted due to aftermath. The very existence of the races becomes an issue. Either Deathwing or lack of resources will end life. War with alliance scales to a new level. No cease fire period is known as of yet. Speculating, it is probable that when Deathwing becomes an imminent threat 'we will all work together against a bigger threat bla bla bla'.
-Garrosh status-> Becomes the new warchief, reshapes the horde and under his rule they undergo the biggest reformation after their initial settle in kalimdor. Fortifies Orgrimmar, boots trolls, kills Cairne and threatens open Sylvanas.
What we have here is a character that has evolved in an epic story. A forgotten orc in some distant planet that learns the truth about the name he bears and eventually becomes warchief, a straight descendant of Hellscream.
Surprisingly this character faced rediculous hate because he..pushed Jaina..and taunted Varian before he taunted him.
I admit that the story isnt complete and needs some filling since it has great potential. The part of Garrosh's life in azeroth with Thrall and the northrend adventures are the obvious fields.
So far, so good. I just hope Garrosh stays a Hellscream and doesnt end like a make love not war hippy cause some people felt offended after he called Sylvanas bitch or mocked Vol'jin.