I think this makes the game a lot easier to visualize consistently and design around consistently rather than have some hit points be one factor (morale) and others another (divine grace) and yet have both healed with something that is described as healing wounds.
I'm not sure how you figure that. 4+ editions so far have managed to fail on the consistent narrative. I know 4e is the outlier so bear with me as I talk in 3e terms (most of this would also be valid in almost all the AD&D I played.)
Exhibit A: Mr. Peasant normally has 6 hp. An monster has clawed him for 8. So he's down. Will likely die (is dead in some editions RAW). Yet, he can be restored to life with a
Cure Light Wounds spell. Seems rather odd that the cleric would choose that spell with Mr. Peasant knocking on death's door, doesn't it?
Exhibit B: Mr. Fighter normally has 100 hp. He has just fought a monster and is down 50 hp. He can move, fight, speak, carry a load, run, etc. just as well as he could before the fight. (At worst, you can say he has a little less staying power in his next fight.) Nonetheless, friend Cleric decides to burn a
Cure Critical Wounds spell in an attempt to heal Mr. Fighter.
"Critical" is defined as follows:
crit·i·cal adjective
<snip movie-critic type definitions>
6.pertaining to or of the nature of a crisis: a critical shortage of food.
7.of decisive importance with respect to the outcome; crucial: a critical moment.
8.of essential importance; indispensable: a critical ingredient.
9.Medicine/Medical . (of a patient's condition) having unstable and abnormal vital signs and other unfavorable indicators, as loss of appetite, poor mobility, or unconsciousness.
<snip physics definitions>
Now, it seems to me that none of these descriptions fit the fighter, but would fit the peasant.
If you're looking for consistency in mechanics, D&D's HP and healing rules are not the place to start, and making every HP partially physical doesn't help much. One of the things that always irks me in the game is that during combat, every wound is a scratch, welt, bruise...whatever. Then, when combat is over, and the Cleric offers healing....suddenly sucking chest wounds open on all the fighters....which immediately close once the Cleric runs out of juice.
That said, I don't have anything better to offer, other than patches like fixing the healing spells to reflect the level of the
target rather than the caster.