As the lowest-level demon creatures growing on the Aifala Continent, goblins and Grey skinned Rats have a lot in common.
Both are small and weak individuals who rely on group cooperation, overwhelming their foes with sheer numbers; both live in dark, damp, dirty undergrounds, driven by their instincts to indulge in their desires.
In a sense, calling goblins "humanoid grey skinned rats," or calling Grey skinned Rats "rat goblins," seems to make sense.
And in actual combat, the experience Xia Nan has from both is quite similar.
Their fragile bodies are like tender green plants under the blades of a lawnmower, not even able to touch the hem of Xia Nan's clothes, as they turn into scattered limbs and fragments amidst the wolf howling wind of the [Teeth Hunting].
The iron-grey Beheading Longsword cuts through the air in a perfect arc, enhanced by forward momentum into a reinforced version of [Vortex Slash].