You can also try my horse crossbowman build. Perfect accuracy while at full speed on courser ( i mean: same as standing still on ground ;D)
Level 30 (4 420 577 xp)
Strength: 7
Agility: 30
Hit points: 42
Converted: 4
Ironflesh: 0
Power Strike: 2
Shield: 0
Athletics: 0
Riding: 10
Horse Archery: 5
Power Draw: 0
Power Throw: 0
Weapon Master: 10
One Handed: 1
Two Handed: 1
Polearm: 1
Archery: 1
Crossbow: 190
Throwing: 1
Light xbow. It is reloading fast, riding fast, has a lot of manouverability and it's accurate.