Intrestingly, I also felt that bisecting the storyxp, just because of the heavy wound, is kind off too much. Isn't receiving a heavy wound and surviving the conflict a very rich experience by itself and worth a certain amount of XP 
(remembers me of the 90ies playing MERP- when you earned the most XP for the wounds/damage you tanked.. -> strangely my players voluntarily wanted to get wounded!?!? 
)
However, in the end we want to do nice character development, which is a major part of ArM5. So killing grogs --- only for increased drama (last year the beloved scout-grog got lost- shocked by the frightening sight of a smoothface roaming the nearby mountains- they found his dead body at the bottom of a cliff.) sad but unforgettable..
@ ouroboros: Thanks for the tipp of Lords of Men, "Mitigating Deadly Wounds" -> it comes close to our confidence/storytelling house rule [url]https://forum.atlas-games.com/t/house-rule-confidence-storytelling/11200/1], paying a CP to avoid (a deadly) combat botch. Maybe I can incorporate something like that 