Darth_Xiane.
If it's just one reader you can probably ignore him/her, especially if the other comments are rather positive.
However, always remember that only 1-10% of a reader base is active in the comment section. For one comment like this there's 10-100 readers that share the same view. If you can improve this scene to make it clearer don't hesitate. Yet, you can't satisfy everyone. If that's the fact that the MC is not the perfect OP alpha male he/she was looking for, there's not much you can do.
I think most fantasy webnovel readers know the difference between goblins, kobolds and orcs, but it is still better to redefine them and have your own take about this to refresh the concept. In some anime/novels, orcs look like fallen elves with dark skin and bestial attributes(Lord of the Rings) , while in some others they look like pigs(japanese animes mostly), or grotesque bipedal monster. Same for goblins. They're generally small, green and ugly with pointy ears, but you can find stories where goblins can actually look handsome and beautiful, barely smaller than a normal human with similar physical traits except for the greenish skin.
So, if you haven't clearly explained these differences from the start, it is indeed advised to do it.