I dont think anyone at any point throughout this thread have stated that you could use the battlefield rules as is to play another period of warfare. Mongoose seems like pretty smart fellows, and I'd like to think noone on this board was that removed from reality.
The whole suppression thing seems to have stemmed from two views, one where only salvoes of automatic gunfire and explosive shells will prevent a unit from doing something, and alternatively the idea that troops in "contact" with the enemy, are naturally limited in their range of options (doubly so when communications drop. In ww2, even the americans frequently found communications to be FUBARed on a regular basis). Friction, as some books term it.
Suppression as written is just one such mechanical representation of the limiting of options that a unit can realistically be expected to carry out, while in "contact", and such limitations were experienced from the earliest days of warfare, and till today.