Remember the Random Dungeon Generator in the AD&D 1E DMG? Not only did it offer the enterprising DM a quick (if not always easy) way of rolling up a dungeon, you also were able to determine the dungeon's inhabitants.
I remember sitting on the floor with graph paper, dice, the DMG and the PH on a Thanksgiving Evening at my aunt's house, rolling out a dungeon and that putting a small party thru it.
That shit was more lethal than anything any of my fellow teenage DMs ever put me through. EGG certainly set things at near killer DM level with the included charts.
Strangely enough, I never seemed to have any issues with 2d6 orcs in a 10' x 10' room behind a locked door.
Come to think of it, I rarely left unoccupied rooms in the dungeons I designed back than. An empty room was wasted space for player expo ;)