If I remember what I read, those grenades Dunlap is talking about were taken out of service because it was too easy to make the mistake of throwing the wrong grenade for what you wanted–In other words, it wasn’t just the Germans who were getting confused. The Brits were, too.

Hell, the polyvalent grenades were taken out of service for the same reason–Under the pressure of combat, it was too hard to differentiate and select the mode you wanted. People would screw it up, and either not kill the enemy or they’d find themselves in their own kill radius.

There are a lot of things that play out in the minds of the designers that just don’t work in reality. It all boils down to the Will Smith quote “I saw that going differently, in my mind…”. Performance only flows from ideation, not actual effect.