What happens if physical damage also causes stun damage? Options

[PriorityKarmaGen]

Proposed houserule: every point of physical damage taken also deals 1 point of stun damage. The stun condition monitor is now 8 + (Body + Willpower)/2. This does not apply for physical damage caused by stun damage overflowing the stun condition monitor. Optionally, dice penalties from damage can be no longer cumulative -- only the higher of the stun or physical tracks apply.

The goal is to avoid the situation where a punch would have knocked someone out (the target had taken lots of stun damage), but because the attacker had bone lacings, it doesn't in fact knock the person out. Alternatively, Tanky McTank took a bunch of stun damage and but no physical damage, so he takes off some of his armor so he'll take physical damage from the bullets. Not only is this annoying from a gaming perspective, it's also tough to wrap my head around from a realism perspective. If the trauma of a normal punch is enough to knock you out, the trauma from a harder punch should also be enough to knock you out, no?

Other effects of this change:

Stun damage is slightly worse since people will have more boxes on the stun track. Combat with only stun damage will last a bit longer.

Physical damage is a bit better. It becomes a lot better if dice penalties are cumulative across tracks.

Armor and armor penetration becomes much more important.

Body is slightly better now. Tanks wouldn't need a high Willpower for their condition monitor, but it's still useful for other things.

Split the damage called shot would need to be reworked somehow.

Anything else? Is there any reason why this would be an awful idea?