Unfortunately, This is just not true, there is no damage reduction to the chest, there's no difference in TTK with same stats on a different WL to a RC WL.
If a CT has Max health to 300, and picks up the super Armor drop from 104th, they'll take more shots to the body than we do
If a CT is 300 100 they take 11 shots to RCs 13 if on 250 200
RC takes 7 Shots to the head to die from 250 H 200 A
This is testing done just on the DC-15A btw