I was playing Bunker 1 yesterday trying to pull a nade when an idea struck me. This doesn't exactly pertain to normal gameplay, but this may be beneficial to LTK players.
In the main control room where the last camera is located, there's a metal crate and a box to the left of it. I tried luring the guards here and i found that i was able to wipe them all out on most runs.
Sure, the odds of getting there untouched are slim, but I just wanted to point this out. Perhaps this could possibly be affective on the runs where the guard doesn't take out a nade.