"Slow"

I don't know man. They got fucked up pretty quickly.

They actually give a reason why in the series; Most Goblins only attack villages that don't have the money to afford the higher ranked adventurers, and said adventurers don't take the goblin quests because the reward isn't worth it. Newer adventurers, thinking the cheaper quests are easier, take these quests thinking they can handle a few measly Goblins. And well, you saw what happens to them.