I cracked open two boxes of moranon orks today, to begin a mordor army for WOTR.

I know I want ringwraiths in the mix. Beyond that I'm a little stumped. Theres a LOT of options available, and some of them feel like a bit of a bad fit to be honest. For example, wargh riders dont look like they'd fit into an army incredibly well, they look more like scouts.

So, simply put, the question is thus:

What stuff did mordor armies actually contain? Are there units that I should probably avoid? are there units that are a must? All so far as fluff would be concerned.