They are in fact monsters, and girls. I see you have not reached the peak of your power. Being serious though, yeah, for most people who are not on the deep end of the scale this probably doesn't deserve the monster girl tag, nor does harem really apply to it; it's kind of like Pokemon with Ash's Bayleaf and how certain traits could be interpreted as attraction but aren't intentional.
I actually like these designs a lot. It definitely is moving outside of the range of what we normally consider a dragon to be, into this much more unique and interesting space. When they say "dragon" in this story, you could really replace it with "monsters", "pokemon", etc. and that would be a much more clear representation of what they are going for.