I usually support mine with some sort of caster. I find nazgul or spectres to be good for moving a model out in the open where you can shoot it down. Being on the platform gives a good line of sight for those 9 shots. Also, try to max out your bow limit with other units (I like trackers
). As far as combat it usually isn't something you can just run into a whole warband alone and expect it to come out okay. Just give it some support whether that is troops or a combat hero is up to you. Obviously don't forget about the monster rules, a cheeky hurl down the spear line can change a game even if it doesn't kill anyone directly!
I've taken out Balin and a bunch of iron/khazad guard with a great beast and some trackers before so always believe in your orc shooting! Hope that helped and good luck.