There's actually a name for what the girls have: "The Curse of Knowledge".
Think of it as the opposite to the Dunning-Kruger Effect: whereas with D-K a person doesn't understand the amount they don't know, with Curse of Knowledge they don't understand that someone doesn't have knowledge that...
High five to my fellow Professional Crazy Person. Went to work one day, and after a little while just... checked out. Apparently I stared at my blank monitor without moving for hours. Been just over a decade since, and I am just now starting to get to what I would consider "normal".
This: terminal velocity depends as much on aerodynamics as gravity. A skydiver can exceed their flat-body terminal velocity by diving at the ground and thus minimizing their frontal area; similarly if the mithril golem is coming in legs- or head-first it could conceivably exceed the local speed...