This page shows a list of consecutive quadruplets drawn in Powerball, ordered by frequency.
There is no difference between Goblins and Orcs as far as being different species. They are basically the same. If I had to name one difference it would be that Goblins are a type of Orc that has developed more to tunnels and caves, whereas Orcs I think of more patrolling in open spaces, such as the plains of Gorgoroth.
I am going to give it a go but it's fugly and there is no way round it. There is more to the horde than just orcs but it seems developers just don't see it that way. Afaik they want to make the garrisons look in the style like Stormwind/Orgrimmar.