Just don't forget that it isn't just any Gaussian distro we're discussing. It's flatline vs. sum of 2 dice rolls. The latter gives barely ca. 2% chance of rolling under or equal 20% damage (negligible damage, either 0 or at least no Fatal Wounds, for 30-40 weapons' power, against unarmored target). This is far lower than even the traditional 5-10% 'something went wrong' chance used in many systems, like Fallout or Warhammer Role Play.
Balancing of armors so they're neither worthless nor overpowered, by the rule of thumb, makes an armor semi-safe if it stops around 80% hits. Against a weapon with 50 power, that requires 80 armor (xcom), 65 armor (tftd) or 67 armor (gaussian 2dice). The range where armor is semi-immune but penetrable clearly expands, which is a good thing. However, the range between half-resistant and semi-immune contracts, which is a worse thing, since in a semi-immune armor, the penetrating damage would be laughable anyway, unless we get into high-end weapon territory.
Medical data alone is not enough to cover all this, since we're discussing armor as well.
