Actually, the whole Soviet masses thing is largely misunderstood by people who aren't familiar with Soviet military doctrine. The reason there is a perception that there were "waves" of Soviet troops wasn't because the Soviets had troops EVERYWHERE and had some sort of hard-on for throwing bodies at their enemies. It was because according to Deep Operations, the cornerstone of Soviet military theory, the breakthrough phase of any operation consisted of stripping all nearby fronts of men and equipment and funneling them into specific axes of attack in one sector.
This was done for several reasons:
1. Since the success of the breakthrough phase largely determined the success of the entire operation, it was of monumental importance to ensure that the probability of failure was at a minimum. One way to do this is to simply outnumber your enemy by a large margin - in that sector.
2. Second, the breakthrough phase was to be achieved with the use of infantry, artillery and very minimal tank forces. Since the majority of Soviet mechanized forces were saved for the exploitation phase, it was assumed, correctly, by Soviet generals that no matter how much they tried to save their soldier's lives, they will still incur large losses. Not because they didn't care (abnormally high troop losses were punishable by execution) but simply because of the nature of Soviet military strategy - specifically, the stringent requirement that the breakthrough phase must succeed.
The good news is that once a successful breakthrough is achieved, exploitation by Soviet tank armies becomes extremely hard to stop. So while it may seem like the Soviets are an innumerable force, they really just took everything nearby and put it into one place. This is the brilliance of the theory, and is a short explanation of why there always seem to be "masses of Soviet troops" wherever they attack.
