Hint: The true key to success is learning what units work well against your enemy's units. For example, Trow work great against Fetch, and use Archers to pick off Wights from a safe distance.
Hint: Use the terrain to your advantage. Place Soulless in locations that only they can reach (like a cliff). Then they can shoot their enemies without fear. Also, an Archer can easily pick off a number of Dwarves if he's standing in the middle of a lake.
Hint: On bungie.net, highlight a player and type ".score" to see their rank and points.