I agree with the op, i find that shadow bat mini bosses at my level 5-shot my character, fly faster than i travel in any direction except down, and sometimes double attack when flying through my character (normal bats do as well). This is really hard to deal with, and impossible for me to deal with in multiples. My first (and only) death has been from those stupid bats running me down in a long hallway and then ducking down through the floor, immune to attacks until they swing around to attack again.
Hopefully, with the extra healing from potions and the bats not being able to duck out, they are a little bit more manageable. Although i hope that doesn't mean that they attack and then turn around to attack again.
Also their hit box seems rather largish, i dont think getting clipped by a wing is enough for them to bite me.
I have only encountered dragons in roving monster bands, and they seem very fun to fight in the open air, and very hard anywhere else. And i also do not understand why their breath attacks spawn well away from the dragon and sometimes on top of me.