Finally managed to win a game at the weekend! It made up for all of the defeats I've suffered with my Warhammer and 40k armies recently. Below are the army lists for the game. I was playing with the Isengard army which performed admirably. The scenario was the 'To kill a king' one from the Legions of Middle Earth book. Saruman and Eomer were the designated 'kings'.
Isengard
Saruman
Lurtz
Uruk Hai Captain (shield, heavy armour)
Warg Riders (x6, some with bows or throwing spears)
Uruk Hai Warriors (x11)
Beserkers (x3)
Uruk Hai Scouts (x8, bows)
Rohan
Eomer
Boromir
Gimli
Warriors of Rohan (x22, some with throwing spears, bows or shields)
Riders of Rohan (x15, some with throwing spears)
My wargs managed to take out the first wave of riders (6 of them) on the charge which enabled them to aim themselves at Eomer fairly early on. My archers were typically off target and, since they were led by Lurtz, I forfeited their bows to charge into some of the Rohan warriors mid-way through the game.
I finally found the usefulness of Saruman by carefully hiding him between the Uruk Hai and then unleashing command and sorcerous blast as often as I could. This dispatched Boromir and Gimli with ease (Gimli lacks the will to defend against this for more than 2 turns) and it was left to the wargs to take out Eomer.
I'm not really sure where the Rohan army went wrong, it seems that an Isengard army is very hard to beat, no matter what the opponent.
Perhaps I will expand the army when the War of the Ring is released in a few weeks time.