So if you can avoid casualties by voluntarily becoming suppressed then the reverse must also apply. You can avoid being suppressed by taking casualties. But should that decision be available to the player? What role is the player taking in the battle? If that of a section/platoon commander then possibly yes. But if you are a battalion or higher commander how do you get your entire command to be willing to die for the objective?
I can see how this option might be available to fanatical/indoctrinated troops (Japanese/some SS etc.), or maybe highly motivated troops (Paras/Commandos etc.), but surely not every troop type in WWII, which would be the effect of such a mechanism, no?
Trust science, not the scientists.