I think MERP can absolutely be lumped into the category of "combat as a fail state." Way more than giving your starting magic-user 4 HP.
Anyway, here's a subsystem for D&D-like games to ignore HP. Each wound sucks, unless you have armor.
I Have No HP (And I Must Scream)After you successfully hit a target, don't roll damage. Instead, roll a d20 and consult the appropriate wound table.
The d20 pops. If you roll a 20, roll again and add the result.
If you roll a critical success on your attack roll, add +10 to your wound roll.
Rolls of 40+ are treated as 40. Rolls of 1 or less are treated as 1. (I imagine all sorts of damage bonuses or penalties can be applied to the wound roll.)
If you are struck, you can choose to sacrifice a piece of armor you are wearing for -10 to the wound roll. This must be done before the wound roll is made.
Bleeding Rules: Several wounds cause bleeding. If you are bleeding, you spend your action to a) make a Wisdom check to bandage yourself or b) use an herbal poultice to stop the bleeding automatically. If you take any action other than "sitting and trying to stymie the bleeding," you must make a Constitution check at the beginning of your action. Take a penalty to your check equal to the number of open bleeding wounds you have. If you fail, you are stunned and lose your action. If you fail three times, you fall unconscious from blood loss. You can bind your friend's wounds, too, of course.
Here are the tables. Open them up for that Google Spreadsheet goodness.
The counter fulcrum to this is that the healing/recovery system needs to be equally diagenic. There needs to be long lists of tables of herbs that "heal lung damage" or "are good for sprained muscles." In a pinch, rest 1 week to recover from most of these effects.
I spent probably too long rewriting MERP criticals into this format. I think this is, like, an "okay" pass, but would probably really be messy at the table. Too much stuff to track. I have -2 to all actions, -1 to AC, and if I run I'll start bleeding? Ugh how much writing do I want players to do? (Answer: Almost none.)
Anyway, I just thought I'd throw the idea out there to see what stuck. Would you use this at your table? How would you make HP and wounds more "diagenic"? How could we finally kill HP once and for all?