Indeed. All valid points, however, consider that Fedayeen troops have target 4, Save-, Kill 6 (or 7, I forget off the top of my head, but we'll say 6 for our purposes)
Being obscured changes this (+1 to kill score) to T4, S-, K7. Since the troops have no save value, they still ALWAYS DIE on a 4+. The obscurement has meant not a jot of difference. In fact, being behind a concrete bunker wall (Save +1, Kill +2 IIRC) still makes no difference, since they don't have a save value.
Adding to the kill score of a unit that has no save value is pointless, since they always die when their target number is exceeded.
The fedayeen seem to be just as vulnerable dancing naked in the road as they are behind a concrete wall.
G.