Despite the huge change in appearance being quite noticeable, what caught most of Daimon's attention about the hobgoblin is the fact that he could see battle aura flowing through its body.
Previously they certainly faced two goblins which could use magic, but that didn't mean they were actual mages, the goblins were classified as magic beasts instead of a rational race, not because of their low intellect.
There are many races who aren't exactly smart but more instinct driven, primitive would be the best way to describe them, some subspecies of lizardmen for example.
And yet they are considered a rational race for the simple reason that they can learn and use multiple spells as well as manipulate mana, the goblin mages Daimon faced previously were only able to use one spell, ice spear and earth shield to be precise.
