As far as Ainz knew, YGGDRASIL’s goblin had all sorts of names and ranged from level 1 to 50. Their differences in strength varied widely, you couldn’t just lump all goblins together. It could be disastrous if you weren’t careful.
Was their relaxed attitude due to their conviction that high level goblins won’t turn up, or were the goblin in this world only that powerful?
“...Won’t powerful goblins show up?”
“There are powerful goblins, but they won’t show up at the forest we are heading to. The strong goblins are usually tribal leaders, they won’t activate the whole tribe.”
“The Goblins also know the human’s area of influence, so they understand attacking en masse would be disastrous. Especially the powerful goblins that are intelligent.”