Good question, it is a little ambiguous.
When I wrote the rule, how you've described it was the intention. Fighting two foes with a strength of 4 each is essentially fighting one foe with a strength of 8. While their strength is combined, their HP pools aren't, so as soon you reduce one foe to 0HP, the foe side has 4 strength. But yes, running into two foes without a certain level of strength and/or HP pretty much guarantees a bad time. Mirroring the Dark Souls inspiration, it's intentionally brutal and stacked against the player.
All that said, I think I prefer the way Jake Zemeckis handles this! It remains punishing on a bad roll, but it isn't guaranteed to hurt you a lot even if you roll well. IMO Jake's version is probably the more fun way to handle double enemies using furtive grasp rules.





























