Advantages:
No immediate change to the HP system, only model and config changes to implement system.
Use the integrated and working material penetration system to simulate armor, no need for mega-extensive scriptwork or sciency stuff beyond what is there.
HP system can then be tweaked to deliver realistic responses to hits in coordination with the existing features (fires, explosions, vehicle component damage.)
It appeared nice when I thought of it and after an hour of pondering I couldn't find any immediate flaws that I as a non-programmer, graphical minded designer person could spot.
Pls input on dis comunity thx <3