3.4.1 A hit from a hand-held weapon counts when the weapon’s striking surface hits with sufficient force. Clarification: taps, grazing, and glancing shots do not count as sufficient force.
These are the criteria for judging if a hit counts. If one swing can hit me in two places, both with sufficient force (and this does happen to me, not infrequently), then both hits are good.
Part of the confusion, i think, comes from the Bel rule: 'A single strike can only damage one Target Area.' There is no rule like this in Dagorhir's rule book, though.
(apologies for the repetition, others replied as I was posting)