Hear me out: a metal 1990s Lara Croft uniboob. Hits are no longer directed to the sternum.
If that isn’t credible enough for you, make the uniboob bigger, redirecting force outward, away from the chest.
If that isn’t credible enough for you, a massive uniboob containing a tiny gnome sorcerer able to slay at range. Basically a lil green skinned tiddy tank.
That’s just called 1600s era half plate.
As halberds and other armor penetrating weapons became normal (and Guns), the focus of armorers was on deflection rather than outright stopping blows.
Also, iron became cheaper and thus mass produced. So in some sense armor got worse, but far more people were wearing armor. The small bits (gloves, legs, etc etc) couldn’t be custom made per person anymore because of mass production templates. But armor was well on its way out by then anyway as guns were obviously the future.
Ok, so the issue with that is it will direct arrow and crossbow bolts upwards towards the neck and face, so you will need to add an angled gorget with a lip to redirect the bolts/arrows.
This was an actual armor design for a while, but it is not as pronounced as you would imagine.
