Not that Mithrandir needs my back-up, but camels rock against horses. As you can see camels lose only 1 point attack when in lush terrain, but gain +2 against horses and +4 defense. Throw into the mix how cheap they are to build and keep, then add a point or two valor and you can see where this goes.

Bedouin camel warriors
Charge 6 Attack 2 Defence 0 Armour 2 Speed 9, 14, 16 Morale 0 Cost 125 Support cost 40

Terrain

+1 atk for camels in sandy desert
-1 atk for camels in lush or temperate
-2 atk, -2 def for cavalry or camel in trees
Bonus to atk for being uphill (amount depends on height difference)
Penalty to atk for being downhill (amount depends on height difference)

Fear of camels

+4 def for camels against horses
+2 atk for camels against horses