So, you got a little knowledge, eh; but with your knowledge you have no understanding.
Weaponized mustard, chlorine, sarin, etc. are totally, absolutely indescriminate. Covering MANY MAGNITUDES of target radius over conventional weapons. Which accuracy is becoming incredibly precise in my lifetime.
But gas and biologicals seep into the hiding places of noncombatant innocents horrifically killing or infecting those who become infectous then spread disease, then killing . More horrific still are nuclear WMD. With the Geneva conventions and nuclear non-proliferation; in the last century mankind has for the first time sought to limit the methods and means of war to recognized combatants only. The killing of civilians cannot be and is not condoned. So for nuclear Mutual Assured Destruction (MAD) was implemented along with non-proliferation to forego another use of nuclear weapons. Treatys banning gas and biologicals were signed.
So OF COURSE the numbers for Sarin are veeery leeetle.
1st Image: Reality
2nd Image: How OuterBanksVol sees himself