fighting a lot of people made his skin soft enough for an arrow to penetrate?
also, please with the u-foes example. don't support the well known troll's opinion on this please. you're a respected poster and i think you know better. We have seen vector alone reduce Hulk to a skeleton and thor was taking his blast along with others after being hit by sentry.
finally even this is a low showing for Thor but in the same month in his book he was taking hits from Doom/Destroyer (I know lower than normal destroyer but still...) without a scratch.
overall in his career I say Thor has durability showings easilly on adam's level (unless we use pre crisis where the marvels were trully invulnerable)