Second, those weren't universal. Only used in specific circumstances (as your link states). And IIRC, largely done away with later in the war after USSR production caught up and they won strategic initiative.
Please. Had USSR had the territorial situation of Poland (Germany to north and west, german allies participating in invasion south and east) it would fall just as well.
No point in sacrificing hundreds of tousands of lives (which BTW Poles did in 1944 in Warsaw Uprising anyway - bad mistake of Polish government).
BTW a lot of USSR early problems with German betrayal were self-inflicted (red terror disposed of big part of educated officers for example, also Stalin prepared invasion of his own - there was infrastructure prepared to attack, not to defend).
http://en.wikipedia.org/wiki/Barrier_troops#Barrier_troops_i...
Hard to expect small casualties when you shoot your soldiers with machineguns from the back.