I'm glad you had a good time with EDE :).
The heuristic behind balancing was somewhere along the lines of "the player should fall back to traps to battle the larger monsters, or when surrounded, or when there's desire to >set up< an area for a fight". I do agree they'd needed some additional thought, because not only they're less straightforward than the other two options, there also is not *that* much danger from the monsters if you keep luring them into narrow spaces. They were viable enough for a game balance that was made in something like two hours ;p.