Sub-10 is pretty dang hard to do, even on AoPc. I can't really imagine this happening for any other kind of run unless you seriously force it, though. Basically, it'd be run for stairs, hit Halls of Carnage for BFG, run for stairs, hope for cells on the way, kill Cybie.
Strangely, playing HNTR for these medals? I would have thought it more appropriate to gain them in N! or something... but then I digress. Maybe the lousier aim of the monsters at HNTR makes it much better to play at this level.
The aim is part of it, yes, but it's really the speed that kills you. The difference between UV and N! used to be (from what I've heard) pretty small once you get past the idea of slowly and steadily killing as much as possible. The new increase of speed, while probably needed, really turns it into a whole other challenge altogether.