Link and Pit both use arrows to the best of their abilities, but they are fundamentally different. Link is a close range fighter who throws out the occasional Light Arrow to keep opponents guessing. Pit has a lot of projectiles at his disposal and typically uses a good ole fashioned Cannon/Arrow technique that does a lot of damage. The main threat to Pit would be the Light Arrows, but his shield will be able to bounce all projectiles back at Link. Not to mention that his flying speed should be enough to dodge the attacks. Pit wins.