If you put Saruman the White instead of Galadriel you've got a faaaaar better force. If this force breaks then Outriders are just C3 heroes (a lot of the time C2 because of Wraiths) and flee very soon, so Saruman's rule will be much help.
Don't know if you know, but an Outrider/Gamling/Saruman list won the 2009 UKGT (
http://venivididouble1.blogspot.com/201 ... story.html), but the list was much more combat oriented and was more versatile than yours. Unfortunately having only bow armed models doesn't serve well in a lot of scenarios where you can't even use those bows because you have to move forward (Domination, Take and Hold, The High Ground to name just 3 and Contest of Champions is a likely loss for you because Galadriel sucks in combat, even the War Aspect one).
If you want to keep it similar to what you have though, then I would have Saruman instead of Galadriel and 2 Outriders and then 6 horses instead of 1 Ranger of the North and 5 Spears.