I feel like durability isn't properly defined

Normally durability is defined as the ability to withstand something, and in a powerscaling context, that something is an attack. And durability is usually assumed to be equal to the attack potency of the attack that the character tanked.

The problem with this definition is that a character can withstand an attack of a particular level (say a wall level punch) but then get damaged by a weaker attack with smaller area of contact (say a needle thrown with street level AP and the character gets pierced by it), so what's the character's durability?

I think the solution is to redefine durability to be more specific, either define it as:

1. "The amount of energy the character's whole body can withstand"(if a character can tank a building level explosion they can be considered to have building level durability even if they can get hurt by a wall level piercing attack)

or

2. "The amount of energy per unit volume the character can withstand" (the amount of energy carried by the attack should be divided by it's volume)

idk which one is better