For example: A villain who is a special monster species who is much stronger than a human but is weaker than someone other of their own species. Are they a Brute or a Weakling then?
If the main characters are humans ; and are weaker than him, the villain should count as a Brute
Simple: exposable minions no one gives a toss about are weaklings, the semi-bosses everyone fears are brutes.
What do you think?