It's magic, there is no logic. This is a magic shop with jars of eye of newt and bat wings and belladonna. In a world where someone's hair can be used to make a doll to control them, there doesn't need to be a logic to fingers.
As for dragon hunting, that's a poor job by the DM,
not making them the fearsome ancient creatures stronger than an ogre and as smart as an ancient wizard in the ways of magic, before you even get to the breath and adamantine-like scales.
I have problems with dragons letting humanoids ride them, though as a "cool thing", I think that's a losing argument!
