Probably it was left out by NCsoft or maybe it is a bug I can not tell , but there are monster groups that makes 0 sense.
BugBears are Humanoids , but are Lister as Giants , Gargoyles in Catacombs are Considered Beasts while Any other places they are Constructs. Some Raidbosses Have description to be undead and name ends like Vangeful spirit , but is humanoid not undead... Stakatos are Insects , but in different places same Stakatos are considered Humanoids (best example in Swamp of Screams) All area are insects you go inside the nest and all monsters with same textures and skins are considered humanoids , same in Forge Of Gods. Since here in l2 there are classes like Warlord or Gladiator that have Detect Weakness skill against specific group of monsters It does affect this game greatly. Is there anything could be done to at least make insect monsters insects and undead well just make undead not humanoids? I do not think this cause any imbalance , because this makes 0 sense while same monsters are considered different group and against some you have advantage and against other you do not.