I approach this issue from a different perspective.
Instead of 0hp being death, a character is unconscious up to a negative hp total of CON - 10. So a character with a CON of 14 would be unconscious in the 0 to -3HP range, but would be dead at -4HP. It has the realism of healthier characters being able to take more damage and still recover, whilst still keeping combat deadly (the critical success can still cause an instant-kill).
I recognise that it might take some urgency out of the game which comes from a situation where is only a few strike ranks to heal a fallen comrade; howeve