They're gigantic for dogs, which still makes them much smaller than goblins. Also, the goblin probably had military skills. Size+skills>numbers when the numbers side only has one more.
I don't know what breed the game represents (poodles judging by their performance
), but imagine stripping naked and fistfighting two "gigantic" Rottweilers!
Let me first imagine that I am a trained goblin soldier who grew up in a world like Medieval Europe, but more war-torn and full of monsters, specifically in tundras, caverns, and/or evil areas, the deadliest areas in the world.
Dogs are okay against smaller wild animals, like badgers. And that was a normal dog, on his own. The problem is, large numbers of dogs does not make them able to kill things large times their size. You need bigger numbers, enough that the dogs latch on faster than they can be shaken off, so that the enemy passes out from exhaustion.