This is why Blizzard sense of scale and proportion pisses me off to no end, as does their unwillingness ro fully explore potential ramifications of their storylines.
->What about ongoing Orc migration from Outland? Garrosh himself ventured to Azeroth past TBC, why others of his kind have been swept under the carpet?
->What about Orc rebels joining the insurection forces? With the memories of first Horde -as hazy as they may be- still lingering as the witnesses are still alive, there HAS to be some notion among orcs that Garrosh's path would doom them all.
->What about other settlements? What is their relation to this power shift?
Still, it is nowhere near as bad as how goblin survivors of Gallywix's prison ship being somehow numerous enough to not only populate a sizeable metropolis along with a district in ORG, but also deal with particularly heavy casualties and loss of life even in the early questing zones. Either Gallywix's ship had the holding capacity of a space colonization vessel, or population of Kezan has been shrunk to fit in as accessories in city boxes or we have a bad case of BS proportions and scale.