Besides heavies, most tank can die pretty fast since the last buff to AT guns. Thing is don´t rely on a singular AT source.
It MAYBE be interesting, on a mod.
It will also be HUGE RNG if your tank dies or not.
1 penetration = boom dead
1 bounce/miss = happy tank (at least for mediums)
With your suggestion, half HP.
-Vehicles getting 1 shot by 100/120dmg (AT nade): Kubel, Armored car, M3, Panzerwerfer, Opel, MHT, Mechanized group HTs, Katys, Ambulance, US HT/Scoutcars, Greyhound, M20...
-Vehicles getting 1 shot by 160dmg (most sources): OKW HTs, Luch, OH HT, US HTs, Su76, T70, M8, Stuart, Priest...
-1 shot by 200-240dmg (KT-ISU-KV2-M36): Puma, Stugs, M36, M10,
-1 shot by 320dmg (Pak43-JT-Elephant): hmmm all tanks excepts heavies?
And i haven´t mentioned mines, tellers, strafing runs, artillery, etc.
I don´t think you have the micro to dodge all what i mention before.
If you want realism, you have MoW. If you want vehicles with less health, you should expect vehicles with double the range + lethality.
