I don't know if this is an issue or not, but is there a way to burn luck to reduce the severity of an attack against a character?
Luck can only be used to modify a roll the halfling player (or thief or whoever else) is making, not a roll made by another person.
We've tried the "modify the other guy's roll" in play. It opens up a real can of worms in terms of "dueling Luck usage":
"I subtract 3 from his roll!"
"Oh yeah? Well I add FOUR so now you're at -1!"
"Okay, fine now I do another -1 to subtract one more point!"
Etc. etc. Not a good scene in actual play. Gets complicated (and, sometimes, very silly) fast.
But, as noted above, if the character doesn't make it that still leaves open one last check for body recovery.